View Full Version : A vdd mod problem - OPP or other specialists please help!!!
A vdd mod problem.
Before installing my brand new nf7-s 1.2 (second nf7-s I own) I decided doing the vdd mod. Just been lazy - not wanting to take the board off the case in a few days again ;)
But with a 10k pot my 1st readout@1.7 vdd (bios) was about 2.17V! What the heck :mad:
Okay. Things aren't that bad... So I did unplug the pot. But... still 2.17 V readout :confused:
Noticed same mysterium after doing the vmem mod on my 1.1, but before all was okay.
Anybody knowing an answer??? I would appreciate it being not ignored.
Thx
SAE
Ruantic
03-16-2003, 04:07 PM
My first thought would be to measure the resistance with DMM, all VR's aren't created equal..... Check for correct resistance and change as needed.. Also in another thread someone accidently turned a VR to its limit and created a dead short, carefull not to do the same.....
Measured the res before installing the pot. 10.35K. That's not the prob.
But even after unplugging it the voltage stays @ 2.17. When turning the pot the voltage also changes very very slowly, so the pot is okay.
At last the nb doesn't get warm @ 2,3V :stick: :confused:
impulse
03-16-2003, 08:58 PM
Originally posted by Ruantic
My first thought would be to measure the resistance with DMM, all VR's aren't created equal..... Check for correct resistance and change as needed.. Also in another thread someone accidently turned a VR to its limit and created a dead short, carefull not to do the same.....
hey, can you point me to this thread? I just bought a nf7 1.2 and did the vdd mod and had the same thing happen i think. I first measured and my voltage was 1.87 and I turned it up a little, after that my voltage reads only .17-.20.
Major
03-16-2003, 11:24 PM
impulse your Avatar is creaping my out man !!!!! hehe
Are you sure your measuring on the right leg of the mosfet ???
Does it boot up ??? I think I'm the one Ruantic was refering too about turning my pot the wrong way and killing my vmem regulator. I burned up my vdd regulator too running it at over 2.1v. I hope you haven't done the same !
Ruantic
03-16-2003, 11:28 PM
hey, can you point me to this thread?
Sorry, cannot find it, either looking in wrong place or it was on the Temp forum, kinda think it was on temp forum...
Da[]San
03-17-2003, 12:44 AM
Confirmation needed.
Lowering resistance = More or less volts?
I've got a 5k VR. With 1.5volts set in bios what will that give me.
Or do i need to use a 10k. Any help is appreciated thanks..
btw my crappy Multimeter only measure full kohms..:(
Ruantic
03-17-2003, 12:56 AM
I think I'm the one Ruantic was refering too
Lol, yeah now that you mention it i remember the details a bit more, and reason i answered after your post is i left the window open so i wouldn't forget to answer it, lol, guess i shoulda hit refresh :eek:
twiggy
03-17-2003, 01:23 AM
Originally posted by impulse
hey, can you point me to this thread? I just bought a nf7 1.2 and did the vdd mod and had the same thing happen i think. I first measured and my voltage was 1.87 and I turned it up a little, after that my voltage reads only .17-.20.
A reboot doesnt fix that? I have that prob sometimes but a simple reset fixes it.
Da[]San- Lower resistance=More volts. As for the pot I dont remember the ohmage Im at so no clue.
Da[]San
03-17-2003, 02:20 AM
Thanks Twiggy - u have put my mind at ease..
I'll measure the mosfet tonight, with my pot set at about 4.5k.
Originally posted by Major Slaughter
Are you sure your measuring on the right leg of the mosfet ???
Does it boot up ??? I think I'm the one Ruantic was refering too about turning my pot the wrong way and killing my vmem regulator. I burned up my vdd regulator too running it at over 2.1v. I hope you haven't done the same ! [/B]
My board is booting up fine. No probs at all. I am sure I took the right leg to solder to. But... the DMM still displays a way too high voltage. There is nothing burnt ... yet :D Knock on wood :brick: :bsod:
But no solution to find??? I can only estimate my voltage ;)
SAE
P.S. Found out that one of my Kingstons does not match the other one. Send it back hoping they 'll exchange it. But a good burnin gave me a stable 231,8MHz 2,0-3-2-2 @ 2,99Vcc in Dimm3(single one). Trying to push it some more...
I only touched the leg of the IC a very short moment. Just had problems with the leg of the mosfet, took a little longer to get the solder hold on it.
Could it be... ???
Ruantic
03-22-2003, 03:30 AM
Its possible but the mosfets are pretty hardy and can typically hold up to alot more heat then ICs (referring to heat generated by soldering) If you don't have any solder globs or loose/shorted connections, and you've removed the mod entirely, and forced a refresh state of the circuit, and it still won't change voltages I guess it seems logical that the regulation circuit might be damaged.
One thing you all want to do when soldering to possibly sensitive components is to make sure to use a decent quality Soldeing iron/station that is properly grounded. crappy radio shack type irons can introduce component threatening voltages to the circuit, its relatively rare but can happen......
I'm having exactly the same problems...what is the cure?
What will my bios @1.7v and my VR @5k give me?What about 10k? And 7.5k? Sorry for the questions, just need to know as I can't read my voltages too!
Originally posted by Ruantic
Its possible but the mosfets are pretty hardy and can typically hold up to alot more heat then ICs (referring to heat generated by soldering) If you don't have any solder globs or loose/shorted connections, and you've removed the mod entirely, and forced a refresh state of the circuit, and it still won't change voltages I guess it seems logical that the regulation circuit might be damaged.
One thing you all want to do when soldering to possibly sensitive components is to make sure to use a decent quality Soldeing iron/station that is properly grounded. crappy radio shack type irons can introduce component threatening voltages to the circuit, its relatively rare but can happen......
I think I bought a good quality precision soldering iron with a very fine tip and 8Watts. Only touched the leg once, like I did the first time on my rev1.1. And there it worked till I modded the Vcc. Then same effect :(
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