P4P800 VDimm Vmod Fluctuates

[Goyo]

Some months ago, make the VDimm VMod : 50K VR or Pot to pin 6 and ground. At 0 Ohms = 0.015V + 3.3V.

At 0 Ohms gives me 3.2V VDimm. But recently I replace the Pot (soldering directly), for a FAN conector to remove the old big potentiometer(47K) and be able to use a mini Pot Cermet Type Multiturn(50K) (those little square blue ones)

But now my VDimm fluctuates. When I run memtest+ 1.15, the voltages are unestable goes from 3.0 to 3.19V.

Before the switch the Pot, I never read the voltages while memtest ran...

So, here is my question:

¿Is that normal?

¿Something is wrong with my Vmod?

I must to say... when I read 3V in VDimm they are stable (VR = 20K, 2.85 in BIOS)

And without VDimm Mod (Pot is removed) have stable voltages.

Thanks in advance...

Greetings :D

[Goyo]

/need feedback ping! :(

[TyphooN]

Yeah, I too had this problem. You need more volts on the 3.3v rail. at 3.62 I get 3.27 stable.. and so on, the more 3.3v the more stable vdimm you can get. Mod your 3.3v rail to 3.6v or so, thats considered safe by many, and you should be stable.

[Goyo]

Thanks a lot TyphooN :up:

Today I'ill make the Volt-Mod 3.3V rail on my PC P&C TurboCool 510Deluxe, I have just received the Pots to switch them.

BTW Thanks to Hell-Fire for the hint :D

Greetings :D

[a5h]

i don't have this problem ...mine is pretty stable

[TyphooN]

good luck on the psu mod :)

[Goyo]

Damn it!, The store made a mistake, they send me the horizontal mount pots, and I need the VERTICAL MOUNT Pots, to do a clean mod.

Well, I just buy others hope they send me the right ones.

Anyway, I'll do the mod with this crap.

When the Vertical Mount arrives, I'll change it.

:-D Thanks TyphooN :up:

Greetings.

[TyphooN]

no problem, i saw your post asking about the vCore read point, did you ever figure out where it was? i posted in that thread but nobody ever answered it. tell me your results after the mod. i can get 3.27 stable at 3.62 on my 3.3v rail, and higher than that higher stable vdimm but i really dont need it.

[Goyo]

Shoot!

Now, the VDimm still fluctuates at 3V

I figure out that my Vmod is Malfunctioning.

I'll return to do the VDimm Volt Mod before making the 3.3V Rail Volt Mod.

greetings :D

[Hell-Fire]

Originally posted by Goyo
Thanks a lot TyphooN :up:

Today I'ill make the Volt-Mod 3.3V rail on my PC P&C TurboCool 510Deluxe, I have just received the Pots to switch them.

BTW Thanks to Hell-Fire for the hint :D

Greetings :D

My pleasure bud. ;)

Let us know what happens.

Make sure you have a solid joint on the mods bud....and make sure you have a good connection to your GND.

[TyphooN]

you should do the 3.3v mod first becuase it will stabalize it for you at 3v.. it really will help you lol.

[TyphooN]

any new results?

[Hell-Fire]

Make sure you are grounded properly and I would certainly recommend modding the 3.3v rail of your psu.

Cooling could be an issue as well.

Is the LM358 that you soldered to getting hot, or is the FET that you check Vdimm at getting hot?

[Goyo]

Ok guys, sorry for the late reply.

I have the correct pots already. I 'll do the 3.3V Rail VMod on the PC Power & Cooling TurboCool510DeLuxe, right now...

Before...
http://www.prodigyweb.net.mx/goyomora/Modz/TurboCool510D/PCBBefore.jpg http://www.prodigyweb.net.mx/goyomora/Modz/TurboCool510D/PotBefore.jpg

After...
http://www.prodigyweb.net.mx/goyomora/Modz/TurboCool510D/PCBAfter.jpg http://www.prodigyweb.net.mx/goyomora/Modz/TurboCool510D/PotAfter.jpg
Done! :D

Now let's see what we have...
http://www.prodigyweb.net.mx/goyomora/Modz/TurboCool510D/V33Read.jpg

gorgeous!!:D it's rock stable :up:

Ok, now have to try on the P4P800D. I remember that the VDimm Vmod at 0Ohm gives 0.15V less than 3.3V line, so I can expect 3.482~ for my OCZ PC3500 Platinum Limited Edition.

query: is it true, that 3.3v rail max is around 3.7v before OVP shuts off?.

I'll testing... yesterday I got a P4C 3.0GHz SL6WU (30caps), my old P4C 3.0GHz SL6WK need 1.725 VCore to run at 250FSB.

TyphooN It seems that the ADP3180 chip, pin 28 is the VCore voltage, I not sure. :(

Thanks a millon Hell-Fire :up: :toast: for the 3.3V rail Vmod and Pots sale hints.

Greetings:D

[Goyo]

Well, I run memtest 1.15

3.3V = 3.45
VDimm = 3.3
VPot = 0Ohms

When I run memtest (#5 and #6) have VDimm fluctuation, goes 3 to 3.27.

Other strange thing...

When I set 3.3Vrail to 3.45V, every goes fine.

After the POST, I saw a list of Strings, displaying very fast!
A: XXX
B: XXX
..... XXX = Random numbers
It seems like a infinite cicle

I Turn off, then my BIOS was corrupted. I already restored..

please help :(