Guide: Power Supply Sense Wire Modding

[Hell-Fire]

Please, note: XS owners and members will not be liable for any damage caused to you or your hardware, neither can be liable for any breach of the warranty.

!!!Remember that even when your computer power supply is off, it has enough current stored in it to kill you. The information presented here is for illustration purposes only. Use it at you own risk.!!!


I have received many a PM and Email asking about modding the sense wires on a power supply in order to grab higher rails. I am sure many other members have as well.

To keep from having to say the same thing over and over again, I have put together a guide that should work for any power supply. I have modded the PCP&C, Antec, Enermax, Aspire, and various other supplies. This mod has worked for every single one of them.

This mod also works if your psu already has internal pots available, but you would like to increase your rails past what the stock pots allow.

Not all power supplies have sense wires, but most do atleast have a sense wire for the 3.3v rail. Also, most power supplies that have a 5v sense wire, but no 12v sense wire are still moddable. In this situation, modding the 5v sense wire will a vast majority of the time mod the 12v rail as well.

This guide was written while modding an Antec TP430.

Abbreviations and other things that may be useful in order to follow this guide more easily:

VR = Variable Resistor (Pot or Trimmer)
PSU = Power Supply
DMM = Digital Multimeter
CW = Clockwise
CCW = Counter-Clockwise
Red Wires in PSU = 5v Rail
Orange Wires in PSU = 3.3v Rail
Yellow Wires in PSU = 12v Rail

==============================================

Materials Needed:

40-70 Ohm Fixed Resistor
10K Multi-Turn VR
Rosin-Core Solder
Solder Iron (25 watt is recommended)
Shrink Tubing
Wire Cutters/Strippers
Hot Glue/Epoxy/Super Glue

Procedure:

Make sure your psu is unplugged from the wall and if it has an on/off swtich, be sure that is set to off as well.

Grab the ATX Connector and look at the 4 corners. One end will have 2 think orange wires running into the corner slots, the other corners will have a thick red and a thick yellow wire running into them. There will also be thinner wires running into the same slots. These thinner wires are the sense wires.

**Note that only one of the thick orange wires will have an accompanying sense wire while the other thick orange wire is alone in its slot. Also note that sometimes the sense wire for the 3.3v rail is brown.**

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/3.jpg

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/12v_5v_Sense_Wirespic2.jpg

Now that you know what you are looking for, go to the top of the ATX connector bundle and find the same wires. Some modders prefer to cut the sense wires inside the psu housing, but I prefer to cut the sense wires outside of the housing as if a mistake is made you still have wire left to work with. Also, cutting the wires inside the housing can make soldering in that tight spot a chore for the inexperienced modder.

A pic showing the sense wires near the psu housing:

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/Sense_Wirespic3.jpg

Cut away about and inch or so from each sense wire so that we can begin modding.

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/Cut_Sense_Wirespic4.jpg

Here is where we want to go ahead and slide our shrink tubing over the sense wires so that after soldering is done we can protect our solder joints and prevent short circuits. If you do not add the shrink tubing at this time, you will not be able to add it later and will have to use another method to close off the solder joints.

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/Shrink_Tubingpic5.jpg

Between these sense wire leads is where we want to add our fixed resistors. I use a 47 ohm fixed resistor. No particular reason why, its just because they can be bought local to me. I recommend using a fixed resistor between 40-70 ohms.

Here is a pic of the 47 ohm fixed resistors I used, as well as the 10K VRs:

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/Resistors_Usedpic6.jpg

Cut the fixed resistor to fit between the sense wire leads, leaving one end with a bit of a longer leg. We will need that extra room in a bit.

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/Cut_Resistorpic7.jpg


Solder the fixed resistor in place. Be careful not to melt thru any of the surrounding insulation around the other wires.

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/Added_Resistorpic8.jpg

Now, we want to add a wire to the top leg of that fixed resistor. Top leg meaning the leg that is connected to the sense wire lead that goes into the psu housing. Since I am mounting my VRs inside the psu housing, it is better to run the wire from the inside of the psu, and to the fixed resistor.

I would suggest a wire length of around 10 inches if you plan on mounting the VRs inside the psu housing. If your wires are to short, you will have a hard time mounting the VRs and also removing the top of the housing should you need to get inside the psu at a later time. A flip side to that is that if the wires are to long, you may end up not being able to close the housing properly. This can force wires into the fan paths, or other problems where the wires may be putting pressure on other internal components.

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/Wirepic9.jpg

It is much easier to solder that wire to the resistor leg if we strip enough of the insulation off so that we can wrap the exposed copper around the leg.

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/Wrap_Wirepic10.jpg

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/Wire_Wrap_2pic11.jpg

Simply apply solder to securely attach the wire to the resistor.

After you have attached all of the wires to the resistors, you will now want to apply heat to the shrink tubing so we can secure our solder joints. I use a heat gun for this, but a candle, lighter, hair dryer can be used. Be sure not to apply to much direct heat as you can easily melt this tubing off.

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/Wires_Shrinkedpic12.jpg

At this step we are now ready to attach our VRs to those wires we just added to the fixed resistors. To prepare the VRs for the mod, you should cut off one of the outter legs...leaving the middle leg and ONE outter leg. The reason is that only 2 legs are needed, and you MUST use the middle leg. I also cut away about 1/2 of the remaining legs to make things easier come soldering time.

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/VR_Legspic13.jpg

You also have to set the VRs to max resistance before soldering them in place. That is yet another good reason to remove one of the outter legs. It prevents you from making the mistake of setting max resistance between 2 legs, but soldering to the improper leg afterwards and having a zero resistance when you fire the psu on.

When attaching the wires, it does not matter which leg on the VR that you use, but I typically use the middle leg as my "hot" leg in the circuit.

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/VRs_Attachedpic14.jpg

You are now ready to attach the wires to the VRs that will serve as the GND wires. These wires should be about 7 inches long.

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/VRs_Ground_Wirespic15.jpg

You should note the hot glue on the VRs. I recommend using something there to help protect the VRs legs as some force will be put on them. You will be twisting the wires while mounting the VRs, and things of that nature. It would be fairly easy to pop a VRs leg off after a few twists. The hot glue provides fantastic strength for the VRs. After soldering the GND wires onto the VRs, covering the solder joints and moving slightly up the wires will make yanking on the VRs a much safer thing to do.

Now that these are attached we can solder them in place to complete the circuit. You can use many things as a GND, but I prefer to solder directly to the GND wires running off the psu pcb. These are easy to get to:

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/VRs_GND_PSUpic16.jpg

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/VRs_GND_Attached_PSUpic17.jpg

We are on the home stretch, so hang in there.

The easy place to mount the VRs is on the inside of the top of the psu housing. Typically, this is the side where the companies place the sticker stating what each rail is capable of, etc etc. There should be ventilation holes on that side that can be used for easy adjustment of the VRs after mounting.

**If your psu does not have vent holes present, you will have to drill holes in the side in order to have the ability to adjust the VRs.**

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/VRs_Mountedpic18.jpg

You can see in this pic how easy it is to adjust the VRs when you use this method:

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/VRs_Mounted_Viewpic19.jpg


Testing:

In order to test out the psu to make sure the mods are working properly, I recommend not plugging it into a motherboard. We can fire up the psu by bridging the proper wires on the ATX Connector. This allows us to safely check and adjust the voltage rails to our liking without the risk of burning a component.

http://img.photobucket.com/albums/v247/persivore/HF%20PSU/PSU_Testpic20.jpg

Depending on which outter leg you used, turning the VRs CW or CCW will increase your voltage now. I prefer to setup my VRs so that CW increases my voltage and CCW decreases it.

Grab ye olde trusty DMM and plug the leads into a molex connector (plugs into a hard drive or fan). Plug the black probe into a slot that has a black wire running into it, and the red probe into a slot with either the yellow or red wire running into it.

Start turning the screw on the VR and watch your voltage climb. Be aware that you may need a few turns to show a voltage rise, so be patient. If you start tuning it to fast the DMM may not be keeping up and you could kick in the psu's OVP which shuts the psu down. If this should happen, unplug or use the psu's on/off swtich and power it down. Turn the VR the opposite direction you were just turning a few turns. Let it sit for a few seconds, then power it back on.

You are now finished with the psu sense wire mod.

:toast:

Please, note: XS owners and members will not be liable for any damage caused to you or your hardware, neither can be liable for any breach of the warranty.

!!!Remember that even when your computer power supply is off, it has enough current stored in it to kill you. The information presented here is for illustration purposes only. Use it at you own risk.!!!

I've uploaded and changed the links to the origional pictures - Persivore.

[enduracell]

this guide rules, very clean work and informative :):toast:

[Hell-Fire]

Originally posted by enduracell
this guide rules, very clean work and informative :):toast:

TY Sir.

Took me a couple of hours between doing the actual modding, taking hte pics along the way, and editing the pics.

Hope it helps those who are diving into the Vmod realm so to speak.

[blinky]

wow i like how u took pics of everything, i think im gonna dapt some of ur methods, like using hotglue, to secure wires in place :)

[bachus_anonym]

Great guide, HF! excellent pictures, close-ups and parts descriptions :toast:
you just can't stop impressing me with your commitment to this forum and all modding community here, can u ? :)
with guys like you, Malves, Holst and others this is just the "bestest" place to hang out and gain experience...

BTW, congrats to you guys on occasion of being promoted to moderators...

Great work, once again... !!!

[Hell-Fire]

Thanks pc_ice, blinky, and bachus.

I love this joint obviously. Take pride in helping its members, as well as being helped by its members.

I consider this the best site on the net for overclocking/modding.

[Sphinx]

Well done! Very important guide!

[DarkManX_BG]

Excellent guide, well done :)

I still have a question though - why is the fixed resistor needed? In the original thread 'bout the sense wire mod, nobody mentioned a fixed resistor...

[Hell-Fire]

Originally posted by DarkManX_BG
Excellent guide, well done :)

I still have a question though - why is the fixed resistor needed? In the original thread 'bout the sense wire mod, nobody mentioned a fixed resistor...


As far as I can recall, the Antec supplies need that fixed resistor or the mods will not function.

I would say most supplies dont need the fixed resistor.

Most of the earlier threads about psu modding had a fixed resistor used as well as the VR. Its prob more habit now with me than anything else. I remember doing my first psu mod and it didnt work without the fixed resistor. That was on my old Antec TP550. Now, it could have been that I didnt do the mod properly to begin with since I was a newb modder at that point, but I almost always use the fixed resistor to save time later on in case it doesnt work without it.

The next supply I work on I will do it without the fixed resistor.

I do know that most supplie do not require it, although I always add it.

[EmineM]

excellent job there.


How far was the 3.3v adjustable :)?
I currently have a Enermax 460 W that does well but Im looking for more :p

[Rukee]

If you love your computer...give it the juice it needs!!
Excellent job Hell-Fire!!
Not only did it stabilize my MB voltage, but I upped the voltage to the Vapo pump from 11.97 to 12.50v. :)
Hell-Fire, you make it sooo simple, even a Rukee could do it.
That`s not an easy task my friend. :)

[Hell-Fire]

Originally posted by EmineM
excellent job there.


How far was the 3.3v adjustable :)?
I currently have a Enermax 460 W that does well but Im looking for more :p


That totally depends on the power supply in question.

On mine, 4.1v is the max before OVP kicks in.


Originally posted by Rukee
If you love your computer...give it the juice it needs!!
Excellent job Hell-Fire!!
Not only did it stabilize my MB voltage, but I upped the voltage to the Vapo pump from 11.97 to 12.50v. :)
Hell-Fire, you make it sooo simple, even a Rukee could do it.
That`s not an easy task my friend. :)


LOL, nice play on words bro.

Glad to hear you got her rolling. Now kick that Vapo in the arse and lets see some ridiculous scores.

[rj2]

hi hellfire.excellent guide.has anyone considered mounting the 92mm intake fan on the psu,outside the psu.this would i think,give you a little extra room for the wiring,and also having the fan back that little bit could give more cooling power,as basically it is right close to the heatsinks on the psu,then perhaps less of a deadspot from the fan.

[Hell-Fire]

I am sure that would work in fact.

Had a few people request I do it that way for them when modding their psu's.

Its a system dependent thing tho as some setups need the room under the psu.

[rj2]

THANK YOU HELLFIRE!!!.i finally got my antec truepower 550 voltmodded today:banana: .i went step by step using your guide & it worked out great.i did put the 92mm panaflo i had swapped out previously,outside the psu.that gave me some extra room for the trimmers.if it will work in peoples cases do it,it feels like the amount of air being exhausted is at least 33% more.i did the mods one at a time,powered up the psu & metered it.right now i have the 12v@ 12.25,5v@ 5.25.when i metered the 3.3 line it was reading 3.36 off the atx connector great i thought,before it was always stuck at 3.28-3.29v.i booted it up,and the 3.3 line is still reading 3.29.the bios is reading the 5 & 12 voltages properly.
.what i did notice is that it took a lot of turns on the trimmers.12v & 5v,before the voltage started climbing. fyi i used 22ga stranded wire.i will have to shut the puter off so i can try and up the 3.3v line & see what happens.i will post back if i am successful or not
thank you again

[jess1313]

Best powersupply Vmod guide out there, hands down(or at least that i have been about to find):cool:

great work as usaual fire. nice pics. very informative. one quetion thought. are the fixed resitors needed? i am running them on all my modded PSU's. just curious. but i suppose if they wernt needed you wouldnt have them:toast:

[Hell-Fire]

Originally posted by rj2
THANK YOU HELLFIRE!!!.i finally got my antec truepower 550 voltmodded today:banana: .i went step by step using your guide & it worked out great.i did put the 92mm panaflo i had swapped out previously,outside the psu.that gave me some extra room for the trimmers.if it will work in peoples cases do it,it feels like the amount of air being exhausted is at least 33% more.i did the mods one at a time,powered up the psu & metered it.right now i have the 12v@ 12.25,5v@ 5.25.when i metered the 3.3 line it was reading 3.36 off the atx connector great i thought,before it was always stuck at 3.28-3.29v.i booted it up,and the 3.3 line is still reading 3.29.the bios is reading the 5 & 12 voltages properly.
.what i did notice is that it took a lot of turns on the trimmers.12v & 5v,before the voltage started climbing. fyi i used 22ga stranded wire.i will have to shut the puter off so i can try and up the 3.3v line & see what happens.i will post back if i am successful or not
thank you again


No worries bud, thats why I am here. ;)

Yeh, it can take a few turns sometimes to get the voltages to start moving. They start to increase faster after that so be careful.

The increase you saw on the 3.3v rail, regardless of the VR bing there, is from the fixed resistor. If you do not get any further increase after adjusting the 3.3v VR, better take a look at the solder joints for that rail, and the ground point of the 3.3v VR as well.


Originally posted by jess1313
great work as usaual fire. nice pics. very informative. one quetion thought. are the fixed resitors needed? i am running them on all my modded PSU's. just curious. but i suppose if they wernt needed you wouldnt have them:toast:


I cant be certain, but I am fairly sure that on the Antec supplies the fixed resistor is needed or the mods will not work. I generally add them just so I dont have to redo the mods if they dont work because I only used a VR versus both.

I do know that not all supplies need the fixed inline with the VR. I pretty much use the fixed to keep from getting a headache afterwards.

I have a supply that someone sent me for my testing bench. I will do the 3.3v mod on it if a sense wire is present. Let you know how it responded without using the fixe resistor.

The next Antec I get, I will do the mod without the fixed as well and see what happens.

[rj2]

then for your help about the 3.3 line.i have`nt taken the psu out yet.i grounded the neg,to the same place in your pix.i tinned the soldering iron every time,and made sure it was a clean connection.ill go back and recheck it tho.

[Hell-Fire]

Originally posted by rj2
then for your help about the 3.3 line.i have`nt taken the psu out yet.i grounded the neg,to the same place in your pix.i tinned the soldering iron every time,and made sure it was a clean connection.ill go back and recheck it tho.

As ridiculous as this will sound, be sure you are using seperate grounds for everything.

Although everything is technically using the same ground, using the actual exact same grounding point can cause weird issues.

[rj2]

i used 3 seperate grnd points.i put a dab of solder on 3 of the pieces of steel in your pix that are holding the grnd wires coming from the pcb.then touched the grnd wire to the solder blob.clean as a whistle soldering wise.

[Hell-Fire]

Should be working fine then I would think.

[rj2]

me again.in the end i was`nt turning the trimmer enough.i have got it up to 3.4 0n the 3.3 line.the weirdest thing is that the bios and mbm still read it as 3.29.i cant figure that out.but at least i know my soldering job and what not was good

[Da_BoKa]

bios readings aren't always accurate, always use a multimeter

[rj2]

i agree.very strange tho that the bios is still misreading the 3.3volt line but is reading the 5.5 & 12 lines properly

[Hell-Fire]

Definitely use a DMM when adjusting the VRs...never trust the bios for an accurate reading on any voltage.

[DarkManX_BG]

Originally posted by Hell-Fire
Definitely use a DMM when adjusting the VRs...never trust the bios for an accurate reading on any voltage.
I second that... a while ago, I trusted BIOS after doing a vdimm mod and thought that I'm running safe 3.02V... it turned out my memory actually got 3.11V, which scared me at that time (now I run 3.2V 24/7, times have changed :D )

[NoX]

Originally posted by Hell-Fire
Definitely use a DMM when adjusting the VRs...never trust the bios for an accurate reading on any voltage.

Is it possible to measure the core and the +12V rail voltages with a DMM when the CPU is running under load?

Thanks.

[Hell-Fire]

Originally posted by NoX
Is it possible to measure the core and the +12V rail voltages with a DMM when the CPU is running under load?

Thanks.

Yes sir. Check the 12v rail by sticking the red probe into a molex connector (plugs into hard drives, fans, etc) slot that has a yellow wire in it, and the black probe into a slot with a black wire in it.

To check the core, I am supposing you mean Vcore (CPU), then you need to check any Chokes and FETs that are around the cpu socket.

Be careful not to cause a short circuit.

[NoX]

Thanks Hell-Fire for the quick reply. I have just a few more questions. Please be patient with me, I am a mech engineer messing around with electrical devices. :brick:
I checked the +12v rail an it fluctuates between 11.9 and 12.2 volts. The vcore droips by .07-.08v under load. Now what would be the benefit of modding the PSU and increasing the 12v? Will this stabilize the vcore?

[STEvil]

may help some.. but if your rails are fluctuating it may be better to get a better PSU.

[Hell-Fire]

Agree with STEvil, and hav another option to consider.

Yes, sometimes modding the rail will help to steady her out a bit.

You need to check to see if the exhaust air is warm or not. If so, you should consider changing out the stock fans for something with higher CFM. The higher the temps get inside a psu, the more the output suffers and stability.

[DarkManX_BG]

Did the mod a couple of days ago, works like a charm. 3.6V is safe for 24/7 use, isn't it?:D

I can confirm that the mod works without the fixed resistor on an Enermax 460W btw ;)

Oh yeah, I did the noobish mistake to solder to the wrong ground wire - I used the one that goes to the mobo instead of the one that goes back to the PSU:lol: how stupid of me. Still works though, as we all know - all ground wires are connected... multiple times :P

[NoX]

Indeed my Allied 500W PS is definitely warm during the day and I noticed that at night, when it cools down, I can push the OC further. Better CFMs may help but probably not that much because the room air temp rises over 30C (California’s summer hell). However, I'll get some better fans, it will help anyway. I am tempted to get the Fortron 530W but I am afraid that it will end up with even worst performance because of its case made of steel (the Allied is made of aluminum). Hmmm, maybe I should figure out a way to watercool the PSU. In fact, I think that what I really need is a vdroop mod for the mobo. I did a lot of research but I couldn't find anything about it. I only hope that Hell-Fire might come up with something about that using his omega skills. :bows:
Thanks for the suggestions.
Regards

[Flib]

Did all of your three Mods hell-fire, it was my first time of solder something....

And as it semms it worked very well

Have the
3.3@3.5
5@5.3
12@12.4


Bios only shows 12.3v at 12v rail, but my DMM shows 12.4v!
Under load only 12.23 in bios but sill 12.40 with DMM?Dmm shows NO Fluctations. Only between 12.37-12.42

[Hell-Fire]

Happy it worked out for you.

I would ignore what the bios is saying the flux is and rely on your DMM instead.

[Flib]

Ok! My Protection on the 3.3 rail is already on 3.8v....
But 3.6v will be enough I think.

That was an exellent guide! Thank you!
Only negative was that it costed so much time *lol* A really marathon-mod as you would say ^^

[Jesus]

One stupid question is teh Voltage in the Molex equal to the one that the ATX connector sends to the MBO?

Just checking cause I'm having a debat with a friend of mine at teh moment he claims that theres a difference and that teh readings that you get forom the Multimeter in the Molex are differnt from those in teh ATX.

[Hell-Fire]

Originally posted by Jesus
One stupid question is teh Voltage in the Molex equal to the one that the ATX connector sends to the MBO?

Just checking cause I'm having a debat with a friend of mine at teh moment he claims that theres a difference and that teh readings that you get forom the Multimeter in the Molex are differnt from those in teh ATX.


There will/may be some difference, but we are talking about in the area of the hundredths place here. My molex shows 12.30v and the ATX shows 12.28v. Same for the 5v and 3.3v rails.

The molex connectors will be slightly higher than the ATX connection.

[Jesus]

OK, Cause MBM is reading 11,98 w. 1,375 VCore and 11,86 w 1,75 Vcore while the Multimeter gives ~12,3, it fluctuates more teh f.a., teh Antec 350W but compesates it with higer woltages.

[Flib]

Same Problem, MBM5 is showing other volts and they fluctate a lot more then the ones from the multimeters.

But can you say that the volts on the molex from multimeter and the ones of the atx connecter are equal under load?

Cant believe that I have nearly no fluctation on the Molex Connecters!

I have got an idea... what about checking the reading points on the mainboard by multimeteR? I think the mainboard tries to measure these points too und shows them in bios!

[Jesus]

The winbond chips measure the voltages, I have a voltage drop of ~0,03-0,05 on load.

[Hell-Fire]

Yes, check them on the board as well as the ATX connector. Be careful not to cause a short circuit.

MBM reads them off the board.

[Flib]

measured on the molex with dmm, on the board with dmm und noticed what mbm5 is saying - here are the results (couldn#t do it for 3,3V,don't know the reading point on my board - an35n ultra)

Molex: 12,40
Board: 12,32
MBM5: 12,30

Molex: 5.30
Board: 5.24
MBM5: 5.30

this is in idle mode! Cant give any results under load atm, because my system isn't stable! (Motherboard isn't working properly)

[Hell-Fire]

The AN35N boards are notoriously hot natured.

Heat could be keeping you from being stable. I would check the SB, and the FETs to see if they are getting hot.

[Flib]

mosfets are ok but sb is getting really hot. Cant hold my finger on it for more than 5 seconds :D

Noticed a strange thing:
When i don't plug in the 12V Connector to the board, MBM5 only shows 11,8 and DMM 12,0V on board! Why so low? Thats a drop of 0,4Volts in IDLE Mode!

This board sucks! Looking for an Infinity or an Abit :rolleyes:

[Hell-Fire]

Well, when you unplug that connector, you are without 2 12v inputs.

You are on the right track with either the DFI or Abit.

[Mod_Evil Br]

My friend,

This mod it serves to my thermaltake font, this one TT420AD, i have that modification of 3.3 sense lines, in now i want mod the 12 and 5 v lines too.

[Alexius H [SLO]]

Hi!
I'm about to vmod my Antec TP430. Will be this ok:
10ohm resistor + 1kohm VR ----> 3.3v line
22ohm resistor + 2kohm VR ----> 5v line
47ohm resistor + 5kohm VR ----> 12v line

Thanks for answers!

[Hell-Fire]

Yes, that should work as well.

Be aware that starting with the lower resistance VRs will boost all the lines above spec and you will not be able to get back to spec rails if you so desired.

That is mainly a point of interest if you are wanting to run the 5v and 12v rails within 10% of spec. Some drives do not respond well to the high 12v rail.

I would recommend using a 5k VR on both 5v and 12v rails.

[Alexius H [SLO]]

Allright, 5k for both it will be. I hope this is the best possible combination, what do you think?

[Hell-Fire]

I dont see why it wouldnt work well for you.

The reason I use the 10Ks is so that I am as closer to spec values before adjusting the VR.

Almost any fixed resistor below 80 ohms is a good choice honestly.

[Alexius H [SLO]]

>The reason I use the 10Ks is so that I am as closer to spec values before adjusting the VR.
Why do you need that (safety, ...)?

[Hell-Fire]

Originally posted by Alexius H [SLO]
>The reason I use the 10Ks is so that I am as closer to spec values before adjusting the VR.
Why do you need that (safety, ...)?


Yes, mainly for safety. A lower beginning value (resistance-VR) forces the voltage up higher than maybe the user would like.

Lets say that all you want is around 12.25-12.5v, but the VR you put in is a low resistance. The lowest voltage you maye be able to achieve is 12.85v or more. See what I mean.

I do the same on many other mods I perform. If the Vdimm says to use a 1K, I may use a 5k-10k just make sure I can still close to the default voltages if I want to.

[Alexius H [SLO]]

I see what you mean.
How can I calculate which voltages will I get when I do the mod? What is the equation?

Edit: Another question: VRs must be set on max resistance, right? And then I lower them.

[pucky124]

hey i have a question u say to put the vr on max resistence to get pretty much stock volts right? y would the psu give the same voltage with a 10k vr set on max and b4 the mod with just the sense wire that has maybe 0.0001 ohms of resistence.

[Hell-Fire]

The sense wire itself has very little resistance, but there are internal resistances at work.

Not to mention the Vregs responsible for handling the regulation of the different voltage rails.

[pucky124]

ok but still y does adding 10k ohms of resistence not change the voltage very much but turning the vr down to say 8k ohms raise the voltage. to my understanding no matter what u do to the sense wires u can never take the resistence down (well significantly anyway) but u say that turning the resistence in the vr down raises voltage.

[Hell-Fire]

Ok, look at it this way instead.

Typcically there is something on the pcb that is regulating voltage/current, versus just using a ton of resistors and diodes.

These ICs are responsible for keeping the voltages per rail within their given specs (say withing 5-10%). Now, we add a resistance there and the regulators think they are not providing enough voltage and increase the current/voltage.

The other case is that we have an internal resistance in the circuit loop we are working on. When you add a VR in parallel with that internal resistance, you effectively lower the overall resistance of the system which increases the voltage. Everytime you adjust that VR you are lowering the total resistance even further which causes the voltage to increase even further.

Simple Case:

Current = Voltage / Resistance (Ohms Law)

If you lower the resistance in a system where the current/voltage are not variable, then the overall current/voltage must increase to even out the equation.

[pucky124]

ok thanks for the help i think ive got it now but couldnt u do that mod on any 12v and gnd wires since they r all in parallel? like couldnt u use an old molex and just run the vr inbetween the 12v and gnd wires (the 47 ohm resistor might still b needed) that would make it really eaasy to enable/disable the mod.

[Hell-Fire]

No, because a straight thru voltage line has no feedback and adding resistance there would lower the voltage.

On a voltage rail without feedback (sense wires, etc), the regulator has already compensated for the internal resistance and is feeding voltage as it sees fit. Adding a resistance into that voltage rail will only lower it.

I use to make my psu mods where you could disable them on demand if need be. I stopped doing that because it was extra work and no1 ever used the switches I installed.

An easy way to make the mod removable so you can get back to stock voltage, is to solder one of the GND (black) wires of an old molex plug to the ground pin of the VR and then plug that into a working molex off the psu. When its plugged in, the mod is in effect...unplugged and the mod is turned "off".

Here is an older mod I performed on an Antec TP550. You can see where I used old molex connectors, and plugged them into those pesky "Fan Only" headers for the mod to become active:

http://www4.ncsu.edu/~rwbradl2/CSC251/images/Antec_TP550.jpg

[pucky124]

now it seems the more i know (or think i know) the more it confuses me. the sense wires were all connected to the respective rails right? now is the vr there to change the resistence between the rail and the gnd or the sense wire on the psu pcb and the gnd? and y dont psu makers run the sense wires internally instead of off the mobo connector?

thanks 4 all the help

[Hell-Fire]

The sense wires are connected to the voltage rails at the ATX Connector, but they are connecting seperately from them on the psu pcb. They are running to respective traces that filter from the Vregs responsible for their regulation.

The VRs are there to change the resistance between sense wire (on pcb) and GND. Which is actually changing the resistance between the Vreg and GND. Think of the sense wires as just a longer trace from the Vreg and not as a totally independent component.

The reason the sense wires run to ATX Connector is to monitor the onboard voltages and to use that reading to maintain those rails at spec.

[pucky124]

thank you i think i finally understand that part i still dont understand how the voltage regulators work but im gonna use google to figure that out because it would take to long for u to explain it to me and im sure u have better things to do

again thanks

[Hell-Fire]

Was my pleasure.

Good luck and keep learning man.

[mysticdrew]

My brand new (kinda shiny) Antec TP550 just arived, and I've been debating on what I need to remove out of my 5.25 bays for that front panel that comes with it, then I found this awsome thread (thanks a bunch Hell-Fire). So if I do the sense mods I wont need the front panel correct?

[Hell-Fire]

No, you wont need the front panel, and in fact it can be dangerous to use it after the mods honestly.

The front panel puts another VR in parallel with the VR you just added....which lowers the total resistance even more...almost to the point of a short circuit depending on the value of the VR.

[mysticdrew]

I almost forgot, without the front panel, how do I get my fan at Max speed then?

[Hell-Fire]

You would need to take off the housing again and solder the fans power wires straight to the 12v wires going into the psu pcb.

You can do this by soldering the red wire from the fan to the yellow wire of the psu. Obviously solder hte black ground wire of the fan to the black ground wires of the psu. You should be able to solder these wires to the silver capped wires running into the pcb.

You can ignore the yellow wires from the fan.

[Boyne7]

that is definately the best psu sense mod ive ever seen.
Im sooo glad i traded my friend now lol, i traded my raidmax 500watt (no sense wires) for his TP430. reason was that the tp430 had problems with his motherboard (abit av8) its almost a shame i have a powerstream 520 on the way, but not really.

[Boyne7]

one more thing, approximately what voltages can be achieved with this mod before the ovp kicks in?

[mysticdrew]

Thanks a Lot HF for this great guide.

Also what do you use for Hot Glue? I've tried High Heat and Multi Temp glue and it doesnt stick to PCB's very well and it's all stringy.

The first time I tried to glue the Pots to the inside of the PSU the glue didnt stick so I sanded the case down a bit so it wasnt smooth and it stuck fine, but I cant really do that to a PCB.

[Hell-Fire]

Originally posted by Boyne7
one more thing, approximately what voltages can be achieved with this mod before the ovp kicks in?


Depends on the psu, but with the Antec TP430:

+5V trip point < +6.5V
+3.3V trip point < +4.1V
+12V trip point < +14.4V


Originally posted by mysticdrew
Thanks a Lot HF for this great guide.

Also what do you use for Hot Glue? I've tried High Heat and Multi Temp glue and it doesnt stick to PCB's very well and it's all stringy.

The first time I tried to glue the Pots to the inside of the PSU the glue didnt stick so I sanded the case down a bit so it wasnt smooth and it stuck fine, but I cant really do that to a PCB.


I use an Arrow Dual Temp Hot Melt Glue Gun and the matching Dual Temp Hot Glue that comes specifically for this particular gun.

The best advice I can give is to clean the area you plan to glue to with Acetone or rubbing alcohol first. Then, apply the glue to the area and use the gun tip to "smear" it around a bit to make sure good contact is being made with the pcb.

This has always worked for me.

[mysticdrew]

ya, i just have one of those $2 guns from walmart heh. I'll look into getting a better one then.

[Hell-Fire]

I definitely recommend something that is Dual Temp.

You can find them cheaply at Lowes, Home Depot, and on Ebay.

[David302]

I have a question, the PSU from thermaltake 480watts not PFC don't have the v-sense wire in 12v rail and the 5v rail, how made this mod work on this PSU or only works in Antec PSU's ???


PD: Sorry if my english is not clear :(

[Hell-Fire]

No, this mod works with ANY psu that has the sense wires present.

And keep in mind that it works with supplies that have 1, 2, or 3 sense wires. All 3 do not have to be present to do a mod.

Also note that sometimes they shove the 5v sense wire in the middle of the ATX bundle versus putting it on the edges. Also, most of the time when only a 5v sense wire is present, that modding it also mods the 12v power rail as well.

I would open the psu and see whats there. You may find that there are VRs already included in the circuitry of the psu.

[David302]

Thanks a lot of reason I forgets open the PSU and look inside the PSU :)

[eclypse]

THANK YOU!!!!! Just what the doctor ordered! Perfect instructions and best of all.. Worked on the first attempt! THank god for that cause i also finally used my sleeving kit at the same time!

Works great on my Antec Truecontrol 550WATT P/S!

Have a beer on me :D

[Hell-Fire]

Glad it worked out for you bud.

Keep modding away...dont stop now. :hehe:

[Espen]

Thanks for the great guide Hell-Fire :=)
Have just moded my Chieftec 420w HPC-420-302-DF PSU, it have only sense wires on the 3,3 line so i couldnt mod the 5/12v.
I was wondering if anyone know a way to mod the 12v on this psu because im getting as low as +11,22v when im running the cpu at high voltage. Moding the 3,3v line didnt help the +12v.
Thanks

Espen

[eclypse]

Wow i'd say just spend some cash and buy a new PS!

[Hell-Fire]

Espen, thats a pretty low line bud.

You can "sometimes" mod supplies without the sensee wires, but you need to open it up and see whats inside. You may get lucky and find it already has trimmers.

Other than that we would need to poke around to see what we find.

[eclypse]

I wouldnt even bother risking your life opening up that power supply with such a low 12v line.. That thing cant handle your computer! Buy something else.

[Jeff7]

bios readings aren't always accurate, always use a multimeter

True words.
My NF7-S rev2 reports the following:
3.3V: 3.15 - 3.23V
+5V: 4.84 - 4.87V
+12V: 11.49 - 11.55V

A multimeter, testing the ATX power connector while the system was running reported:
3.3V: 3.31V
+5V: 4.98
+12V: 11.99V

I wish I could measure what the CPU and DIMM voltages actually are.
I do wonder why motherboards aren't made with better monitoring hardware. I mean, they've got incredibly advanced technology all over the place, but they can't do what any cheap voltmeter can do?

[eclypse]

I think testing it that was is still taking a reading off the P/S and not where the voltages are being used form the M/B.

[Jeff7]

I think testing it that was is still taking a reading off the P/S and not where the voltages are being used form the M/B.

So at least my power supply is putting out good voltage then, right?
Might those Motherboard Monitor readings in fact be accurate, from the point of view of the monitoring chip?
Could upping the PSU voltage slightly help increase the low voltages reported by MBM, without causing significant (besides that caused by normal overclocking) damage?

[flyersguy85]

what exactly are the benefits of modding a psu?? my thermaltake gives out 18A on the 12v rail...i have a OCed 3200+, flashed X800 PRO to XT, and ram is overclocked...will i get better performance in overclocking by doing this? or are theese mods only for if your psu can't meet your power needs?

How can i tell if my psu isn't powerful enough?

[Hell-Fire]

The benefits are typically more stable rails, and the ability to overclock ram further.

On most boards the ram is powered on the 3.3v rail, and since the Vdimm can never rise above more than 0.2v less than whatever the 3.3v rail is at, if you want say 3.45v on the Vdimm, you need a 3.3v rail of atleast 3.6-3.7v to be stable.

Also, not all psu are actually running what levels they should be...and dont trust the bios to give you the right readings. The 5v and 12v rails may be running well under their ratings.

[NapalmV5]

Awesome guide Hell-Fire, :worship:

Modded my Enermax 651's 3.3v rail thanx to your guide.

[spaceman]

Excellent stuff, Hell-Fire, thanx! :toast: I'm looking at doing the 3.3v and 12v lines on my PCP&C 510 Deluxe. Now my question is, would this be better, worse, or no diff, from changing out the VRs already there? I was just looking at the other thread, before I saw this. And if I just do the sense mods, can I use another VR WITH the one already being there, on the PCB? Sorry for being such a n00b, but I saw where you said too many VRs isn't good. And finally, if it's best to just change out the stock ones with 2k ones, can I just buy a couple from you? The Radio Shack's around here have very limited stock, and they always seem to be out of whatever I'm looking for. :rolleyes: ;) Thanx again. :)

[sparkie34]

Just modded my 3.3 line tonight. Cruising now at 3.6. Now i'm able to give my ram up to 3.5v. Thanks Hellfire for the help on this mod and the vtt mod.

[Hell-Fire]

Excellent stuff, Hell-Fire, thanx! :toast: I'm looking at doing the 3.3v and 12v lines on my PCP&C 510 Deluxe. Now my question is, would this be better, worse, or no diff, from changing out the VRs already there? I was just looking at the other thread, before I saw this. And if I just do the sense mods, can I use another VR WITH the one already being there, on the PCB? Sorry for being such a n00b, but I saw where you said too many VRs isn't good. And finally, if it's best to just change out the stock ones with 2k ones, can I just buy a couple from you? The Radio Shack's around here have very limited stock, and they always seem to be out of whatever I'm looking for. :rolleyes: ;) Thanx again. :)


Thanks bro. =D

I would recommend swapping out the internal VRs, although adding an additional VR wont hurt things either. It all depends on how comfortable you are with removing the stock ones versus doing the sense wire mod.

I would be glad to send you some, but I dont have any on hand..in fact I ordered some 2 weeks ago and they havent shown up yet..thanks for reminding me..lol.

You can get them from CircuitSpecialists (http://www.circuitspecialists.com/prod.itml/icOid/7558) among other places.


Just modded my 3.3 line tonight. Cruising now at 3.6. Now i'm able to give my ram up to 3.5v. Thanks Hellfire for the help on this mod and the vtt mod.


My pleasure sir. :up:

[spaceman]

Awesome, I'll order some up, thanx. :cool: Yeah, I'm not an expert solderer, but changing them out is probly better. Not only would they be good & sturdy on the PCB, but I wouldn't need to drill any new holes, lol. :D Edited: Zoinks, they're only .79 each, but shipping would be $9! Maybe I'll pursue this further locally. :rolleyes: :D

[Hell-Fire]

Just be careful not to drop any solder balls down into the psu while removing the stock ones bud.

[spaceman]

Just be careful not to drop any solder balls down into the psu while removing the stock ones bud. Roger that. I'll just throw a wet towel behind it. Doh, no wait, that's for soldering pipes, lol. ;)

[elec999]

WIll this mod work with any power supply or most of them. ALso if I want stable vcore and vmem volts will I need to mod the 5v rail and the 3.3. I am also modding the motherboard.
Thanks

[mgv101]

I couldn't stand the poor timings on my RAM anymore so I've finally decided to mod my enermax EG475P-E's 3.3V line so I could hit above 3.1 Vdimm.

Well... the mod did not work for me :(
I've tried it with and without the fixed resistor and made sure all the soldering was done properly but still, no matter how much I turned the pot the voltage wouldn't budge at all.

Maybe this PSU is special as I've also realized that there are no Vsense line for the 12 and 5V rails.

[disco_bazoon]

Excellent guide, with excellent pics!
Got the parts I needed to do this today, so I will be doing it ASAP.
:banana4: (yes, I felt you deserved the bob marley banana :D)

Oh, one thing, would it be okay to use 20k VR's aswell? Got more of those than the 10k's
Also, in some other guide I saw, he used different resistors and vr's for the different rails. Large ones for the 12v rail, small ones for the 3.3v rail. Any point in that?

[Hell-Fire]

If there is a sense line, then the mod should work if done properly.

Cam you post pics of your mod?

[disco_bazoon]

Well, I did the mod yesterday, and it worked out fine. Everything seems to work okay, running the 3.3v @ ~3.6v, 5v @ ~5.3v and the 12v @ ~ 12.6v.
The only problem I have now is that the harddrive activity light lights up slightly all the time, lol. Any idea why that would happen?

Edit: Stupid me, a molex had fallen off my dvd-rw, causing the hdd activity light to be on all the time :p:

[enduracell]

Here is mine (antec 480 true blue). Thanks for the guide Hellfire once more.
I just have to recommend not to use 50ohm R and 10K VR on 3.3 but 10Ohm R and 1K VR for better accuracy and control (10K VR is to fast on turns when u go 3.5 and up and OVP may occur accidentally)

http://www.xtremesystems.org/forums/attachment.php?attachmentid=18546

:toast:

[THunDA]

Im planing on doing this with my pc power and cooling 510 non deluxe.. Right now I maxed the stock pots for 12v and 3.3v.. The 5v one on the bottom seems to have like a glue on it and doesnt wana move so I dont wana force it.. But this is what im getting using a multi meter..

3.39v 12.33v 5.17v

My intensions are to be able to get the 3.3v rail higher cuz im getting a DFI UT this week and wana feed my bh5 good ( like who doesnt ).. Now Ive read your other thread Hellfire, that requires changing those pots.. Now to be honest im not capable of doing something like that.. My soldering skills are just not good enough.. So Ive decided to go this route.. I was thinking of only doing the 3.3v sense mod since my other rails seem ok..

The only thing im wondering in the pics you provided above .. Where you soldered the ground.. I cant get to that part on mine, It seems like Id have to take it all apart to get too it and I dont think I should..

Is it ok if I ground it to any black wire in the bundle of wires coming out of the psu ?

Ok then I have one kinda off topic question hope its ok..

I wana change the fan thats in it with another I have..

Could I just wire the replacement to the existing wires ?

The fan thats in there is a Nidec Beta SL 12v 0.22amp and the one I wana replace it with is a Mechatronics 12v 0.48amp..


Thanks alot for any advice you can offer :)

THunDA

[zaubara]

Wow, thats great! I love it and will try it out ASAP on my new Enermax Noisetaker 475W. Thanks!! :D

[spaceman]

Ok then I have one kinda off topic question hope its ok..

I wana change the fan thats in it with another I have..

Could I just wire the replacement to the existing wires ?

The fan thats in there is a Nidec Beta SL 12v 0.22amp and the one I wana replace it with is a Mechatronics 12v 0.48amp..


Thanks alot for any advice you can offer :)

THunDA
I'm using the same fan in my 510 Deluxe. No you can't use the existing wires feeding it, they don't send enough juice. I just ran the fan wires through one of the fan's mounting holes, then back into the puter case, and spliced on a molex. Works great, you'll get MUCH better airflow, but you just have to be a little more careful if you pull the PSU again. I always leave the side off my case, but if you run the new molex through a PCI slot, it should be easy enough to work with. :cool:

[THunDA]

I'm using the same fan in my 510 Deluxe. No you can't use the existing wires feeding it, they don't send enough juice. I just ran the fan wires through one of the fan's mounting holes, then back into the puter case, and spliced on a molex. Works great, you'll get MUCH better airflow, but you just have to be a little more careful if you pull the PSU again. I always leave the side off my case, but if you run the new molex through a PCI slot, it should be easy enough to work with. :cool:



So I can just leave the existing plug from the factory fan just unpluged in the psu ? .. and run wires from the fan out of the psu to a molex...

Thanks alot.. :)

THunDA

[spaceman]

No prob. :) I just redid my 3.3v pot. I used old fan header wires, and thought crimping them to the legs of the vr would be fine. :rolleyes: Once I did it right, by soldering them, my 3.3v rail gives me 3.93v now, with no load. :D Live & learn, I guess. ;)

[zaubara]

I would like to know if any1 knows if I need the fixed resistor on my Enermax EG475AX-VE(G)! Any1 of you already succeeded in doing this mod on such an Enermax?

I only have a 1/4W 47ohm fixed resistor ... will this one work aswell (instead of a 1/2W 47ohm FR)?

Thanks :)

[disco_bazoon]

I would like to know if any1 knows if I need the fixed resistor on my Enermax EG475AX-VE(G)! Any1 of you already succeeded in doing this mod on such an Enermax?

I only have a 1/4W 47ohm fixed resistor ... will this one work aswell (instead of a 1/2W 47ohm FR)?

Thanks :)
Yes, a 1/4w is fine. There's not much load going through that line anyway.

[zaubara]

Yes, a 1/4w is fine. There's not much load going through that line anyway.

Thanks. :)

I just did the mod and ... well ... its a no-go. :( I have tried it with and without the fixed resistor ...
Before the mod, my 3.3V rail was at 3.37V ... with the fixed resistor only, both resistors and the variable resistor only all give me the same results: no more than 3.43, no matter HOW low i set the VR!

I was thinking of opening the PSU and see if there are any potis already in there and the mod is therefore not working ... but thats what I found at extremeoverclocking.com:

Inside the power supply we can see the Enermax quality in design, components, and assembly. Unfortunately there are not any pots for easy voltage adjustment, however that shouldn't be a buying decision for most people. Please note that opening your power supply will void your warranty (and you can possibly harm yourself), so don't do it!

Any ideas? :(
Thanks for your help!

[THunDA]

I just modded my sense line for the 3.3v rail.. But the weirdest thing is happening.. When I power it on by jumping the green and a black wire it it comes on.. But when I try to read it with the multi all the voltages comes up like this.. -3.14 -12.17... They all have negative in front of them now.. I used a 10ohm fixed and a 1k VR..

Any ideas what I did wrong..? It looks all good and I followed the instructions good..


Thanks
Thunda

edit..

Well.. I just dont have good luck with volt modding I guess..lol I undid everything except the fan I changed out and its the same way..:( Ill put the stock fan back tomorrow and see if its better.. Otherwise I go by something with adjustable pots and burn this thing...

Nothing to do with your guide Hellfire its very good .. Im just too inexperienced to do sh1t like this I guess..

[disco_bazoon]

You're getting that minus infront because you're using the negative probe on the positive wire ;)
The red probe (plus, or positive) on the orange wire for the 3.3, and the black (minus, or negative) one on any ground wire. That should remove the minus ;)

[THunDA]

You're getting that minus infront because you're using the negative probe on the positive wire ;)
The red probe (plus, or positive) on the orange wire for the 3.3, and the black (minus, or negative) one on any ground wire. That should remove the minus ;)


No way man.. I swear I had it right.. im not that dumb.. :confused:

I will double check it tonight.. but im like 99% sure I didnt have it backwards..

[disco_bazoon]

Hm, well, that's the first cause that drops into my mind...
What kind of ground point did you use for the mod? Which one did you use to measure? I don't see how you could do anything that converted the voltages to minus :S
So my guess is that the readings got messed up somehow...

[spaceman]

Be sure to "zero in" your DMM. When you first turn it on, hold the 2 contacts together until it reads "0", and it calibrates it somewhat. :)

[THunDA]

hmm.. lol.. maybe i am that dumb.. came home today and checked them.. all is good.. but I took the mod off last night..lol gona redo now.. :)

edit..

YES !!!! man im so happy.. just redid it and its working perfect.. I only did the 3.3 rail so far.. But had it as high as 3.6 without a problem.. :)

Gona to the others now..

edit#2.. lol

Ok I did the 5v one also.. didnt do the 12v since my psu doesnt have a sense for it.. But I have them set like this for now..

12v = 12.35v ( maxed stock pot )
5v = 5.3v
3.3v = 3.5v ( Had it as high as 3.6v without a problem )

Thanks for the help all..

[zaubara]

I couldn't stand the poor timings on my RAM anymore so I've finally decided to mod my enermax EG475P-E's 3.3V line so I could hit above 3.1 Vdimm.

Well... the mod did not work for me :(
I've tried it with and without the fixed resistor and made sure all the soldering was done properly but still, no matter how much I turned the pot the voltage wouldn't budge at all.

Maybe this PSU is special as I've also realized that there are no Vsense line for the 12 and 5V rails.

... same.
I will retry the mod that afternoon, but I dont think it will work this time ...
Do you have any ideas why this doesnt work? I am also not able to raise my VDIMM above 3.1volts, even though I'm using a modded BIOS that allows me 4.0V VDIMM! :confused:


-- EDIT --

As expected - a no-go.
I can only adjust between 3.37V and 3.43V ... when i turn the VR fast, I notice a short increase to 3.50V and then it drops down again to 3.43V ...
Looks like Enermax has included some kind of overvolt protection into the PSU? Is there any way to bypass it?
Or do you think I simply did something wrong on my Enermax EG475AX-VE(G)?

Thanks =)

[disco_bazoon]

hmm.. lol.. maybe i am that dumb.. came home today and checked them.. all is good.. but I took the mod off last night..lol gona redo now.. :)

edit..

YES !!!! man im so happy.. just redid it and its working perfect.. I only did the 3.3 rail so far.. But had it as high as 3.6 without a problem.. :)

Gona to the others now..

edit#2.. lol

Ok I did the 5v one also.. didnt do the 12v since my psu doesnt have a sense for it.. But I have them set like this for now..

12v = 12.35v ( maxed stock pot )
5v = 5.3v
3.3v = 3.5v ( Had it as high as 3.6v without a problem )

Thanks for the help all..
There you go mate. Knew you could do it! :toast:

[Hell-Fire]

zaubara,

I have yet to come across a psu with built in OVP that kicks in at such low voltage.

I would retry the mod and make sure you are using a good ground point. Also check the VR you are using to make sure it is functioning. Those things are made hundreds at the time, could be faulty.

[sang]

zaubara,ive got an Enermax 475AxVe SFMA V2.0 with the 3.3 v moded.My 3.3 line its moded to 3.68v.OVP kicks @ 3.73v
All u need to do its to cut the orange vsense line(teh thinner one) at 7-10cm above the atx connector. Then find the thinner black line and strip 1mm isolation from it,at the same distance from atx connector like the orange one.And solder a 10 kohms VR between the stripped point of the black line and to the upper part of the orange vsense line. The other end of the orange vsense line(who goes to atx connector) - just isolate it with care.
Before u'll start the PSU,be sure to set the vr to the max resistance (@10k).

I hope it will be helpfull.:)

My problem its now how to deactivate the ovp circuit of this PSU and feed my 3500 L2 Mushy to > 3.7v .Maybe someone who already done it will help us.

[elec999]

I am having a hard time finding the sense wires, on my psu all the wires seem the same thickness, and there are three for the 12v, I am not sure which one is the sense wire.
Thanks

[elec999]

I can see the problem now, for the power supply in the photos, there is a thick and thin wire coming out of the 3.3v sense, 12v sense 5sense. My psu only got the thin wires, does this mean there is no sense. Is there any other way to mod "a universal mod" that works with any psu.
Thanks

[Hell-Fire]

Please post a pic of the wires.

Also, have you opened it up to see whats inside?

[moparacer]

I have a aspire 520W power supply and it has the ATX connector color coded like in the link below.

http://www.hardwarebook.net/connector/power/atxpower.html

There are no vsense wires from what I can tell. How do you go about modding this? I opened it up and dont see any pots to adjust it internally. I did the direct 3.3 vdimm mod on my mobo and really need to bump the 3.3 up for my BH5. I think I may have the same thing going on that elec999 is asking about?

[Hell-Fire]

Post a few pics of the inside and maybe we will get lucky. :D

[moparacer]

There is as good as I can get with my junk camera lol.
Cant see anything that looks like any pots to adjust. :(
Let me know if you need any close ups for certain areas and I
will see what I can do.



http://images5.theimagehosting.com/Cap0005.1.JPG

[Hell-Fire]

There is as good as I can get with my junk camera lol.
Cant see anything that looks like any pots to adjust. :(
Let me know if you need any close ups for certain areas and I
will see what I can do.



http://images5.theimagehosting.com/Cap0005.1.JPG


Whats the markings on the chip to the top left under the fan plug?

Also, be sure to look carefully for smaller VRs. People make the mistake in looking for the standard rectanlge blue VRs, when a majority of the time if its a factory pot it is soldered to the pcb and is a single turn VR with a phillips head adjustment cap.

Identify the 2 things I pointed. The one thing I pointed to with an arrow might be nothing, but cant tell so thought I would ask cause it looks suspiciously like a single turn VR.

[moparacer]

The one you drawed a arrow to is a small capacitor and the one you circled has no adjustments and is is marked IC202 on the board but I cant make out the part number on it. If we cant come up with anything I might just bite the bullet and order a new PS with adjustable rails. Which do you recommend?

[Mussels]

hello from a newly registered member.

doing this mod, and am semi-experienced in electronics, but have hit a brick wall modding the 12V line on my antec trueblue 480.

40ohm resistor, two 5K VR in series to make 10K total, and it refuses to budge the 12V.

the only thing that i have done different, is my VR is soldered on the ATX plug end of things, and not the PSU side of the fixed resitor. could this have any effect?

yes the VR's work, yes its connected to earth properly, and yes im stumped on this one.

i'll check back here over the next few days, to see if anyone replies.

[Hell-Fire]

Yes sir, that is the difference. The VR has to be on the opposing side of the fixed resistor.

Given that you indeed have the 2 5K VRs connected together properly, as soon as you redo that circuit with the VRs on the psu side of the fixed resistor, you will be able to adjust the 12v rail.

[Mussels]

could this be why 1 in ten or so n00bs screw it up? doing the same thing as me?

and just so i know WHY, whats the technical reason that it doesnt work?

[THunDA]

Well .. Ive been busy but I just wanted to post some pics of my sense mod..

With Hellfire's guide even I was able to do this..hehe..


http://img35.exs.cx/img35/1503/4d-psumod.th.jpg (http://img35.exs.cx/my.php?loc=img35&image=4d-psumod.jpg)


http://img35.exs.cx/img35/9785/77-psudone.th.jpg (http://img35.exs.cx/my.php?loc=img35&image=77-psudone.jpg)


Thanks again HellFire.. :)

[nubian]

i've done this mod with an antec true power 430.
it worked for a couple of months.
not my fans and power supply cooling fans are not working.
why would that be.
it still powers up and all but the fans do not work.
any ideas?
thanks in advance

[nubian]

bump...anybody?
please?

[Hell-Fire]

Take a look at the 12v rail and make certain it is powering.

Other than that, I would say the fans bit the dust.

[iddqd]

Hey, Hell-Fire, I noticed you did the mod on an Antec PSU. I was going to throw mine away for a PCP&C510D, but now having second thoughts. First of all, what was the maximum 3.3 you could get out of that thing? Any way of making it go to at least 4.2V? How about a PCP&C? Or OCZ 520?
i've done this mod with an antec true power 430.
it worked for a couple of months.
not my fans and power supply cooling fans are not working.
why would that be.
it still powers up and all but the fans do not work.
any ideas?
thanks in advance
That is a common problem with Antec power supplies, I'm afraid. They used El Cheapo fan controllers, which all, inevitably fail (mine didn't work out of the box!). What you do, is get different fans and wire them directly to a 12V rail, to prevent any such failure.

[Hell-Fire]

I dont recall how high it went, but fairly high. You can check the specs on the supply to find out the trip point for OVP.

I would get the OCZ supply before the PCP&C one. I had a PCP&C 510 Deluxe and it was awful. Fluxing rails under heavy load and high voltages. Not stable as the OCZ is.

[iddqd]

I dont recall how high it went, but fairly high. You can check the specs on the supply to find out the trip point for OVP.

I would get the OCZ supply before the PCP&C one. I had a PCP&C 510 Deluxe and it was awful. Fluxing rails under heavy load and high voltages. Not stable as the OCZ is.
I thought the resistor was to trick the OVP? What components should I select in order to maximize 3.3 line adjustment (resistor, pot?) on the Antec?

[Hell-Fire]

I thought the resistor was to trick the OVP? What components should I select in order to maximize 3.3 line adjustment (resistor, pot?) on the Antec?


No sir.

The resistors are there to force the regulators on the pcb to force more current to the rails. OVP is handled seperate from these rails.

Try a 10ohm resistor and 1k vr.

[iddqd]

No sir.

The resistors are there to force the regulators on the pcb to force more current to the rails. OVP is handled seperate from these rails.

Try a 10ohm resistor and 1k vr.
The PCB inside the power supply?

Ok a couple more things - is there any way to remove/trick OVP in the Antec? What's the maximum adjustment you can get on OCZ PS520 (such as wire something that runs at 3.3 to the detector, or put a resistor there)? OCZ says it's 3.6, is that due to the OVP they have? If so, is there any way to remove/trick the OVP on the OCZ?

Edit: I know there's a way to get rid of the OVP on PCP&C510D, but you're saying that's a bad PSU.. :confused:

[pleenmeel]

Dear modguru (hell-fire)
First of , excuse me for my poor english (I'm from Holland)
I'm new to the forum and man am i glad there is such. I really need help here.

I've got an Qtechnology PSU Gold blue fan (QT03400G).
I've also got an Asus P4c800-E dlx.(vdimm modded and vdroop modded)

I've done de 3.3v sense wire mod on the psu but since there are no 12v and 5v sense wires i could perform the mods for those 2.
So I opened the psu and discovered that there where 2 very little pots looking at me. Started tweaking them and measring the volts on a spare molex. with nothing or 1 drive hooked to the psu I got the following.

12v ~ 12.28
5v ~5.08
3.3v ~3.61

I was happy with the 12v and the 3.3v but when i hooked the psu up to my rig I started having trouble.
My rig:
- Asus p4c800_e dlx (mods done)
- P4 3.2Ghz with zalman cu7000 now @3600
- Radeon 9800pro @ 9800XT With zalman vf770
- 4x 60gb in raid with promise TX2000
- Lite on 52x24x52 burner
- Nec 3500 Dvd burner
- Philips DVD player
- 80 GB wd in swapunit
- 1gb lan card
- Satellite card
- 3,5" drive
My bios measured the following when every thing was hooked up

12v ~ 11.631
5v ~4,941
3.3v ~3.58 (nice)

A spare molex showed me
12v ~11.91 :confused:
5v~4.4 :mad:
3.3v ~3,56(still good)

I've included some pics of my psu. Could you please help me out as to find a solution to my problem. I think if there is a way as to replace/bypass the tiny pots, I could bump up the voltages, right???
My harddisk are clicking because of the 5v /12v I think.

Many thnx in advance.

[Cyrus The Virus]

hello I have a question about this mod.

In my rig I have a 20 to 24 Pins converter (new mobo and 1 year PSU) is it possible I mod the 3.3V sense wire on the converter (because I am not want to mod my PSU) and take the ground of a black wire ??

[Hell-Fire]

Unless there are sense wires in the converter and ATX connector running off the supply, it will not work. There has to be a way for the signal to get from the converter to the supplies regulator.

Also, if there is not a sense wire on the cable running from the supply, even if there were to be one on an extender/converter that was modded, the mod would not work. The pcb of the supply has to have a sense wire present for this mod to work.

[rhino56]

i think you are an alien because the stuff you were touching got a slime layer all over it
http://www4.ncsu.edu/~rwbradl2/Vmods/VRs_Mounted.jpg

haha j/k

awesome guide here, very easy to follow and understand.
great work HF

[I(illa Bee]

Thanks, great guide...I was scared because a wile back (at lest 6 mounths, i tried this on the same PSU, and fried my Nf7 mobo... .. but this time is worked like a charm....

I didnt bother with the 12v line, it allready runs 12.2v under load and idel my DMM reads is 12.9.... I cranked the 3.3v to 3.42 for now, and my 5v. to 5.3v. Ill probely need more 3.3v when i get my water cooling up and start really overclcoking this 3500+, but i still need to figure out why my baord is undervolting the CPU,,lol

http://server2.uploadit.org/files/KillaBee-PSU1.jpg

http://server2.uploadit.org/files/KillaBee-PSU2.jpg

http://server2.uploadit.org/files/KillaBee-PSU3.jpg

http://server3.uploadit.org/files/KillaBee-PSU4.jpg

[eclypse]

Anyone done this to a Zippy 700 watt? :)

[REDKEN]

Hi guys!
I need some help here. I killed my PCP&C (don't ask) and bought myself a 510 OCZ Modstream. I tryed to do this mod on it but it didn't work.
I did everything by the book, but it always gave me a 4.50v. I don't know what I'm doing wrong.

[Hell-Fire]

Can you post pics of your mods and of the psu?

Post pics of the psu's atx connector and of the inside of the psu.

[REDKEN]

Can you post pics of your mods and of the psu?

Post pics of the psu's atx connector and of the inside of the psu.

I'll post pics as soon as I can retrieve my camera (lent it to a friend). For the moment, using a trial and error method I managed to set the PSU to 3.77v using a 10ohm and a 1ohm resistor in series which is about 0.05v less that what I'm looking for.
What I need now is a way to make it variable. After I finish writing this I'm going to look for a 15 or 20 ohm VR (if they even exist).

I'll see about those pics as soon as I can.

Thanks!

[I(illa Bee]

FRAD, the ground wire and the + wire are backwards..... pod (+) gose on middel leg...

[Hell-Fire]

Frad, can you post a pic of the entire ATX cable as well please sir. Showing the ATX connector up to where you did the mod.



I'll post pics as soon as I can retrieve my camera (lent it to a friend). For the moment, using a trial and error method I managed to set the PSU to 3.77v using a 10ohm and a 1ohm resistor in series which is about 0.05v less that what I'm looking for.
What I need now is a way to make it variable. After I finish writing this I'm going to look for a 15 or 20 ohm VR (if they even exist).

I'll see about those pics as soon as I can.

Thanks!


Yes, they make VRs as low as 10ohms. You can get them from DigiKey.com. They have COD ordering and delivey is fast.


FRAD, the ground wire and the + wire are backwards..... pod (+) gose on middel leg...

Shouldnt matter as long as its ground properly. You can send the live wire to either leg and it will work just the same.

[I(illa Bee]

Shouldnt matter as long as its ground properly. You can send the live wire to either leg and it will work just the same.


well, his isnt working, i would sugest doing it with the POS in the middel....to my knowledge, its dosnt matter wheather the groups on on leg 1 or 3, it will just make it backwards, as you know.... obviously...

But i did one a wile back like he did, ground in middel and i did not work, when i swaped them, it worked.....

[Hell-Fire]

If redoing the VR so that the hot wire is going to the middle leg and that makes it work, then most likely the original solder joint was "cold", or something else was causing a problem elsewhere and resoldering the connection fixed something else you didnt see.

A resistor is a resistor...whether it be a fixed value one or a variable one. Doesnt matter which end you use as they do not have a polarity until after the current begins to flow.

Heck...at this point may as well try it. Got nothing to lose Frad.

From what I can tell in your pics, you have the wire running to your VR soldered to the top of that resistor you added. Thats what I wanted to check out. When this mod doesnt work for people, about 75% of the time they have soldered that wire to the bottom of the resistor.

Not sure what else to say other than to redo the mod when you have the time. If that doesnt help, then I would guess that maybe there is a controller limiting the 3.3v rail to what it is now. A 3.3v mod is one of the most straight forward there is. If it isnt working then only a hand full of things can cause it to not funciton.

[I(illa Bee]

well, your right, a resistor is a resistor, dose the same thing no matte what way shape or form...

Your guss is as good as mine.... ? what kind of PSU is it?

[Hell-Fire]

Its a chieftec 360w.

Ya know one thing it could be is a defective/blown VR.

Frad, replace the VR with a new one and see what happens. Be sure it is set to max resistance between the 2 legs you plan on using. Go with a 1k-10k VR.

[Hell-Fire]

I hear ya man.

GL with it. As far as I can tell from your pics the mod is correct.

[RocKer]

@Hell-Fire

First of all,that is a very good how-to you made there :thumbsup: ,you :rocker: man.

Q,

I only need the 3.3v rail to be raised to let say 3.3/3.4v,do i need to do the mod also on 5v rail and 12v rail,maybe for some reason i dont know,or is it ok that i only mod the 3.3v rail.

The psu i wont to use is a,Q-Tec 550w dual fan Gold(do you need a pic of it),specs are 3.3v=30A,5v=40A,12v=20A,the 3.3v rail(orange) is the onlyone with a vsens.

Is this a good idea to use the Q-Tec(peak watt is 285w,yes i know its low) or is it better to use a Chieftec 360w,becaus the Q-Tec psu's are not known for there good performance isn'it,but the are the only 2 spare psu a have so i want to use them you see,psu in my a64 rig is a ocz 520w and thats a cranking good psu i may say,i love it.

O yes and can i use a 20K vr instead of a 10K vr,you also say that you used a 25w solder iron,i only have a 15w solder iron is that ok or is it better to use a 25w one.

Sorry for the noob Q,but i have to learn it sometime isn'it;).

[Hell-Fire]

Depending on your needs, and money situation, use whatever best suites what you have to work with.

You can certainly mod just the 3.3v rail and be absolutely fine. In fact, I rarely push my 5v and 12v rails to more than 5-10% of spec. It just isnt beneficial a vast majority of the time.

You can use any soldering iron you want to bud. But I highly recommend nothing more than 25-30w for a beginning modder as its just to easy to ruin something with a hot iron.

Your 15w is perfect for this type of job bud. Also, you can certainly use a 20K VR, but be aware that the voltage will increase quickly as you adjust the VR because the resistance will decrease much quicker per turn.

Let us know if you have further questions and good luck bud.

[I(illa Bee]

what would you say a Max 3.3v raisl should be? Hoaw about a mAx, for a system that is everyday uses compuer, Gamming, modding, overcloking, interner/mail....

This is not my garage test system, so i dont want to kill it?

[Hell-Fire]

You should keep it at around +0.25-0.3v above your max Vdimm setting.

If you dont push the Vdimm above 3.1v, then teh spec voltage of 3.3v-3.4v will be fine.

[I(illa Bee]

Yea my TCCD dosnt like anythign higher than 3.1v so...yea...

Do i have any option besides DDR booster to get 3.0v to my RAM? Abviously i can jsut link it to my 3.3v line...and the board max is 2.85 (2.91v)

[Tom DeLonge]

Hi all. My first post here :D

http://freeweb.siol.net/delonge/3,3Vsense%20mod.JPG

I've modded my Chieftec 460W Super Power PSU 3,3Vsense like on the pic. but I have a problem. Vrail before the mod was done was 3,43V (3,15V Vdimm on DFI LP UT nf3 250Gb with 10/15 bios), after mod was done Vrail is 3,33V. What I'm doing wrong? Is possible that VR wasn't soldered good enough on GND or resistor?

A little offtopic... Vdimm with that bios should be 0.1-1.15V lower like 3,3Vrail. Mine is 0,3V lower :eek: WTF is going on with my mobo & PSU? Plz can u help me...

Tnxxx

[Hell-Fire]

Main thing is that you should be using a 47ohm resistor not a 50k ohm resistor for the fixed resistor. Be sure the VR has good solder joints and that you have it set to max resistance before soldering it in place.

[Halomarine99]

Hell-Fire- why dont u answer my PM's bro?

no answers from you for over 3 or 4 monthes... with no replies


you still owe me money, and that power supply was mine that u used for this too

[OnDborder]

Man, I can't seem to get this going.
I'm now trying to do the 3.3 line on an Enermax 431 ps for practice before I do my pc&p ps. The sense line that is coming out the atx is brown but in with an orange 3.3 line. Does this matter?
I'm using all the parts needed in the start of this thread. Set the vr to 10 with a dmm, grounded the vr on the outside leg, and tried the fixed resistor both ways, still no go.
What could I be doing wrong?

Edit: My 3.3 rail was bad to begin with. So I tried with another psu and it worked..

Can you ruin a psu with doing this mod incorrectly?

[sin0822]

Um if you add resistence to the line doesnt the psu give more power?

Antec Neo POwer, Resistor or no?

[OnDborder]

3.323 without resistors. 3.43 with the fixed 47ohm resistor only on my test/practice psu.

[EmoAddict15]

Now this was working for a while there and after a while my PSU seems dead (Antec 480w) I tried tunring it on with the sense wires cut off, and i just read in another thread I may have killed the psu. I dont have a Multimeter to test it but the green/black shorting trick doesn't do any good. Is there anywhere in particular I want to start looking and pinpoint what exactly died in the psu so I could just solder a new part in :P. (Little poor atm)

[-=j0nnyr0773n=-]

Funny how he's in here everyother post until someone sez, "Hell-Fire- why dont u answer my PM's bro?

no answers from you for over 3 or 4 monthes... with no replies


you still owe me money, and that power supply was mine that u used for this too"

I don't know the guy, but he seems like a good guy till u see a post like halomarine99's, oh and this one...
http://www.xtremesystems.org/forums/showthread.php?t=57543

I'm gonna follow his guide myself to mod my True Blue 480w, at least he's good for something ;)

I find it strange that no one can find him :hm:
I hope things work out 4 u marine let me know if ya need help hehe

-=j0nnyr0773n=-

[iddqd]

I finally got around to doing this mod on my Antec tp480. The 3.3 line goes up to 3.99v, and then OVP kicks in at 4.0v and shuts it down. I used a 10Ohm fixed and 10k 63-turn VR for the 3.3 line, and 47Ohm fixed 10k 63-turn VR's for 12.0 and 5.0 lines, although I don't really need to adjust those. Anyway, it seems to work fairly well right now. I haven't tested it with my system right now, because I need to do some more mods to get it working. Done with the power supply, though. Or I could mod it to a modular PSU, like all the rage these days. I don't know how long I can run the antec 3.3 at 3.99, but hopefully it won't explode. If that happens, I'll just have to get a PCP&C 510D, and do a mod to increase the adjustment from stock adjustment (btw, does anyone know where to find the guide for that???? PM me!).

Now this was working for a while there and after a while my PSU seems dead (Antec 480w) I tried tunring it on with the sense wires cut off, and i just read in another thread I may have killed the psu. I dont have a Multimeter to test it but the green/black shorting trick doesn't do any good. Is there anywhere in particular I want to start looking and pinpoint what exactly died in the psu so I could just solder a new part in :P. (Little poor atm)
Did you re-route the PSU fans when you did the mod? The problem with TP480's is faulty fan control system. It inevitably fails, causing your fans not to spin, and the PSU to overheat and die. Sometimes, spectacularly (i.e. - fire, etc). Sometimes just stops working. Either way, my fan control system was :banana::banana::banana::banana:ed up right away, so I re-wired the fans to a normal 12.0 line, and it's been fine ever since. Of course, I had to replace the fans, as the stock ones are noisy, and sound like jet engines if you run them at full speed.
Edit: Why the hell is hell-fire banned? I thought he was an XIP and everything. WTF?!

[e268]

I modded my Antec 380W a while back, only the 3.3v line. I can only adjust to 3.46V which is just under the 5% limit, beyond which the OVP cuts in and shuts it down. I wonder how you can get 3.99v which means your OVP is somewhere around 20%.

[iddqd]

I modded my Antec 380W a while back, only the 3.3v line. I can only adjust to 3.46V which is just under the 5% limit, beyond which the OVP cuts in and shuts it down. I wonder how you can get 3.99v which means your OVP is somewhere around 20%.
I suppose. But it shuts the PSU down at exactly 4.00v... so the max I can get is 3.99 (fluctuates between 3.97-3.99) but i think it's the varying pressure on the test pins more than anything else.

I can post pics if you don't beleive...

[e268]

Don't get me wrong. I do beleive what you said. All I am questioning is how a psu can have 20%OVP protection, which is so much higher than the normal +/- 5%.

[iddqd]

No idea.
http://www.xtremesystems.org/forums/attachment.php?attachmentid=32742&stc=1
Edit: I calibrated the multimeter myself.
Edit2: I mean, against known voltage... So that I know it measures correctly.

[zaubara]

zaubara,ive got an Enermax 475AxVe SFMA V2.0 with the 3.3 v moded.My 3.3 line its moded to 3.68v.OVP kicks @ 3.73v
All u need to do its to cut the orange vsense line(teh thinner one) at 7-10cm above the atx connector. Then find the thinner black line and strip 1mm isolation from it,at the same distance from atx connector like the orange one.And solder a 10 kohms VR between the stripped point of the black line and to the upper part of the orange vsense line. The other end of the orange vsense line(who goes to atx connector) - just isolate it with care.
Before u'll start the PSU,be sure to set the vr to the max resistance (@10k).

I hope it will be helpfull.:)

My problem its now how to deactivate the ovp circuit of this PSU and feed my 3500 L2 Mushy to > 3.7v .Maybe someone who already done it will help us.

Hey!

Sorry for answering that late, but I didnt read the forums for a while now.

I tried to mod my PSU that way - and it works! It really works... I still can't believe it. ;)


One weird thing remains: my multimeter shows 3.5V, but my BIOS shows only 3.35V and allows me to have 3.2V on the RAMs max - which is kinda confusing to me. :(

Anyone recognizes these issues?

Thanks alot, bye

[Tonic]

Do anyone see photos on first post? Did their server broken down?

[chainhoe]

yep, pictures are down...

[Rezag1000]

Are we gonna get the pictures back because I cant see myself doing this mod without pictures as a guide :(

[chainhoe]

could someone please draw an electrical schematic of this mod? because initial pictures are down i dont really understand whats going on. i tried PC-Ice's guide but ended up with 3.55V max on 3.3V line - anything further and it backed down to 3.3V. used 10kohm pot and 47ohm resistor.

PSU - 420W Enlight

[e268]

You should be happy to get 3.55v, because normally, there is a 5% overvoltage protection beyond which the psu shuts down. (3.46v should be the max)

Here is a electrical schematic. Hope this can be uploaded so you can see.

Edit: sorry, cannot upload schematic.

[Tonic]

Send it to me via e-mail, I can upload it

Various PSUs have various OVPs. Also I see that better quality PSU is, higher OVP is. That's why a lot of Antec/Enermax PSUs
can pump above ~3.7-3.8V

[e268]

I think in those cases where higher than 3.46v is obtained, thise psu must have a higher overvoltage protection which may good or bad.

Your profile does not allow email to you.

Here is another try to upload:

[Tonic]

Now I see this pic

BTW, this fixed resistor mustn't be 33 to 47ohm, I have VR set to 100ohm and mod works fine

Damn, looks that no one knows how to modify OVP :( I might to try see track of sense wire on
PSU's PCB, maybe I will find something interesting.. I must pump to 4.0, it's very nice voltage.. ;)

[chainhoe]

well, my PSU doesnt shout down. if i turn VR after i reach 3.55V it just jumps back 3.28V. im clueless.

[e268]

Altho I did not design the mod, but my understanding of electronic circuit tells me that fixed resistor and the VR acts as a voltage divider, sending a lower sense wire voltage back to the psu which causes it to up the 3.3v line voltage, hense cheating the ovp as well (I maybe all wrong here, but this is my educated guess. Please correct me if I am wrong, HellFire).

I set the sense wire mod to give me 3.46v and when I plug it into my DFI nf3 UT 250GB board, the board does not boot. I have to lower it to 3.4v and can only get 3.3 vdimm in bios.

This is a dead issue for me. I can only oc my 2x512 Muskin Blue to 230@ 1:1, 2,2,2,6,1T at 3.2vdimm. I think my cpu is holding me back. So, I don't think higher vdimm will help me at all. Got to wait for upgrade to DFI NF4 board and better cpu with better mem controller.

[Tonic]

Altho I did not design the mod, but my understanding of electronic circuit tells me that fixed resistor and the VR acts as a voltage divider, sending a lower sense wire voltage back to the psu which causes it to up the 3.3v line voltage, hense cheating the ovp as well (I maybe all wrong here, but this is my educated guess. Please correct me if I am wrong, HellFire).

It's reasonable, but tell me, if you modify voltage on sense wire and modify OVP, then what's shutting PSU?


I set the sense wire mod to give me 3.46v and when I plug it into my DFI nf3 UT 250GB board, the board does not boot. I have to lower it to 3.4v and can only get 3.3 vdimm in bios.


Did you try to increase voltage in OS? I've heard somewhere that a high voltage on +3.3V rail can make
PC not bootable, but increasing in OS works

[e268]

Have not heard of OS voltage.

[Tonic]

OS isn't a voltage, nor program related with voltages, it's a system software (Windows, Linux etc.). What I'm trying
to tell, is that if you set +3.3V rail to, for example, 3.6V, your computer can not boot. If you lower to 3.3V, it will
boot. If you're in Windows, then you can increase to 3.6V and it will work. Just at startup 3.6V is too high, at system
software it's fine.

[Rezag1000]

Why are the pictures all gone in the first post?!?!?!?!?!?!

[Tonic]

Because their server has broken? ;)

[fackinlogins]

Come on!!!! Put on the pictures at the first page! Or at least put them all in .rar or .zip so we can download them!

[timpanogos]

I read all this through carefully ... but then stumbled upon this .... I mod'ed to this as I actually liked the idea of the pots tie-wrapped to the bundle inside (heck ya need to be inside to measure voltage anyway).

but one way or the other, here are some pictures that also apply to that which has been lost here:

http://www.bleedinedge.com/forum/showthread.php?t=1021

[chainhoe]

got my problem solved - switched to 5kohm pot, 10k was a bit too much for fine-tuning. id way 2.5kohm would have been perfect for my PSU

[NetZeroZeus]

Can this only be done on the 3.3v rail?
Cause I would like to raise the volts on my 12v rail, it's only 11.89 idle, and drops to 11.76 under load.....

[e268]

You do the same to the 12v rail, as in the 3.3v rail. However, 11.76 is within the +/-5% range, I would not do it. My 12v line goes down to 11.64 on load.

[NetZeroZeus]

I kinda made a mistake, I just measured again, and it's 11.63 constant under load, I turned on the Tornado fans and the Delta 120mm GHE, plus 2 more 80mm fans on the RAM, so I think under full load I am kinda a candidate to change it, but what I want is a digital readout in the front of the case, and the pot right next to it, so under load I can slightly up the voltage, because I am getting pretty unstable because of it, the ATX 2.0 specification only allows a deviation of 1%, I am getting 3%, it's probably also hampering my overclock, I just need a pin-out of the ATX connector, anyone have one?

[fackinlogins]

hi all, my friend had the thread saved almost half a year ago on his PC, so he has the pics... I managed to get it on the server.. check them out if u wanna to http://public.carnet.hr/~ftoic

[kiwi]

fackinlogins:
Thanx a lot man. I needed pics so much :D

[fackinlogins]

fackinlogins:
Thanx a lot man. I needed pics so much :D

u wlcm dude :)

[persivore]

I've uploaded the pictures from fackinlogins and changed the links, so the pictures in the first post should work now :)

[fackinlogins]

okay, nice to hear.. anyway, just a Q: what happened with your pics? You got hacked or what? I wasn't on this site at least 4 months, and when I came back, there were no pics...

[aasmaukr]

Thank you for this mod, hell-fire!
Works like a charm, but i can't get the 3.3v rail lower than 3.49v, i used a 10k potentiometer. It doesn't really matter, since i am going to get a couple of bh5 sticks soon, anyway.

[zbogorgon]

very nice guide, i did it on my Antec True 480, worked perfectly, time to change PSU, i'll go for Enermax 600W Noisetaker and did sb perform this mod on Enermax Noisetaker PSU, does it work, how does it perform? thx.

[e268]

If you are going for a new psu, why won't you buy one with adjustable rails? I recall seeing some mentioned here in the forum.

[zbogorgon]

the only PSU i know who has that is OCZ powerstream, i want to have two seperate rail, so powerstream 600W, it kinda has a bad reputation at the moment and I am from Slovenia, Europe, OCZ PSUs are extreamly hard to get, even in Germany and it would cost me twice the cost of Enermax.

[phixie]

hi all,

First of all i want to thank hell-fire for this nice mod.
I am thinking of doing it with my own PSU cause my pc isnt stable at the moment. Reason? 12v rail is giving me 11.6-11.7. All the other rails are ok.
But now when i checked for the sense wires, i couldnt find one except the one of 3.3v. What can i do?

[wacky]

same here.. I guess u have native 24pin psu like me (i have OCZ ModStream 520w).. there is only orange sense wire, right? so.. where are u profi guys? We need your help, please.. how to mod 5v and 12v rails on 24pin psu?

tnx

[sluggo]

Sorry if this has been covered before, but I thought I'd chime in on the operation of the mod. Some of the explanations are simplified, but the concepts are accurate.

The PSU only knows what it's putting out because it compares it's output to a known 12 Volt reference voltage that's built into the supply. Inside the supply, this reference voltage is connected to one side of a resistor and the sense line is connected to the other side of the resistor. If the sense line is equal to 12 Volts, then there is 12 Volts on both sides of the resistor and no current flows through it. If the sense line is lower than 12 Volts, a very small current flows from the 12 Volt source through the resistor to the sense line. If