EVGA nVidia 8500gt

[merkin]

Started to get Blue screens which blamed the nvidia driver.
Also blocks of pixels and individual pixels would change colors creating a scrambled mosaic before the bluescreen would occur.

Some research brought me here.
There are 5 caps labled as follows: (Fluke 87V cap measurements)
(1x) 7D
OCR
330 (431)
16v

(3x) FZ75
1500 (1745, 1752, 1738)
6.3v

(1x) FZ73
1000 (1174)
6.3v
I am sure there are some tolerances, but are these bad?
Found replacements for the 4 caps with 6.3v ratings. However the closest I found for the 16v cap is a rubycon 330uf 35v and rubycon 470uf 16v. Which of the two rubycon are the best replacement? Is it better to stay close to capitance or voltage? Or should I keep looking through my junk for equal capitance and voltage?

Thanks in advance, merkin

[Scenic]

Re: EVGA nVidia 8500gt

dont bother about the caps. the GPU itself is toast.
nvidia had a huge fuckup with the G84/G86 GPUs (that includes everything from 8400GS to 8600GTS)

once you see a pixel mess, driver stop errors/bluescreens, or random freezing, that GPU is done for..

http://www.theinquirer.net/inquirer/...ia-g84-g86-bad

http://www.theinquirer.net/inquirer/...misery-deepens

http://www.theinquirer.net/inquirer/...sets-defective

[Scenic]

Re: EVGA nVidia 8500gt

too late to edit.

OCR sounds like Lelon OCR polymer caps.
FZ is Sacon FZ = pure junk.. replace on sight.
(if you're gonna try your luck with the caps)

edit: if you registered your card you could also try a RMA
http://www.evga.com/support/warranty/

[seanc]

Re: EVGA nVidia 8500gt

If the caps aren't blown and you can't get an RMA:

Remove all heatsinks, capacitors if possible and melty bits. If you can't remove the caps, cover in layers of tinfoil.

Prop the four corners on some oven proof dishes, with the processor side up, put it on an oven tray and bake it for 8ish minutes @ 200˚C.

VERY GENTLY take it out and let it cool for an hour, then test.

If it works, you've got a card for a bit longer, if it doesn't just throw it in the bin like you were originally going to do.

I cured an 8800GTX this way, not given it much abuse, but it definitely does work now.

[merkin]

Re: EVGA nVidia 8500gt

My part number ends in -LR.
Only 2 year warranty and this card is at least three years old.

So basically i need to reflow the BGA's?

Did this with the xbox 360. I used standoffs and put the board on a flat aluminum cook top with temp controls. Then used a painters heat gun on the top of the board. Shot some liquid flux underneath the BGA chips with a hypodermic needle. My fluke 87V measures the temps quite well.

Thanks everybody ill keep ya updated.

BTW no one answered my question about the replacement caps in the OP.

[seanc]

Re: EVGA nVidia 8500gt

Have they blown, yes or no?

[merkin]

Re: EVGA nVidia 8500gt

Have they blown, yes or no?

No

[yyonline]

Re: EVGA nVidia 8500gt

However the closest I found for the 16v cap is a rubycon 330uf 35v and rubycon 470uf 16v. Which of the two rubycon are the best replacement? Is it better to stay close to capitance or voltage? Or should I keep looking through my junk for equal capitance and voltage?

What series Rubycon did you find for the 6.3V caps? Sacon FZ should be replaced with MBZ or better as per the specs. That's not to say the specs are accurate, but if it was designed for a cap with those specs, best to replace it with something with similar specs, but more reliable. Rubycon MBZ/MCZ will work fine. Other Rubycon series are likely not low enough ESR.

OCR is a polymer cap. Replace with something like Sanyo OSCON, Chemicon PS/PSA/PSC, or Nichicon LF/LG, FPCAP.

Topcat carries OSCON:
https://www.badcaps.net/store/produc...products_id=78

The others can likely be found at Digikey and Mouser.

All that said... I'd expect this is not a capacitor issue, and agree with what has been said earlier. Sounds like your GPU is fried. Blue screens, artifacts, and random patterns are the signs of this. Not uncommon for GeForce 8 series cards. Then again, caps usually aren't too expensive, so it can't hurt to try.