Geforce 8600 gs graphics card, failed repair

[xad]

So I have a geforce 8600 gt (en8600gt) fanless graphics card that was giving me problems, it would cause artifacting in videos initially but then constantly freeze and lock up and sometimes go to blue screen. I uninstalled the nvidia drivers and the computer would start up in VGA mode and it worked but it was very sluggish. I noticed some capacitors looked bulged so I ordered some more and replaced the bulged capacitors but when I restarted the computer it would not turn on instead the red VGA LED would light up.

I tried again to turn it on and it only started up once but the screen was terrible there was so much artifacting and after that it would not turn on again instead the screen would be black. So I took the new capacitors off and put the old ones back on and I still got the red VGA light and the computer monitor would not turn on.
I put the new capacitors back on but this time I replaced a few more old capacitors that looked fine so in total replaced eight capacitors but still I get a red VGA light and the monitor does not turn on.

I've added photos of the capacitors the old one is the brown one the black one is the new one what did I do wrong, initially at least the computer would start up in VGA mode but now it doesn't turn on at all.

I think I killed the graphics card competely so ordered a cheap one from eBay, but just curious as to what I did wrong here to make things worse as I got 6.3v 820uf capacitors, same as the old ones. I tried the card in a different computer and the screen would not turn on also.

[stj]

Re: Geforce 8600 gs graphics card, failed repair

where did the new caps come from?
can we see a foto of the top of it.

[xad]

Re: Geforce 8600 gs graphics card, failed repair

I got it from eBay here: http://www.ebay.co.uk/itm/300494581145

I've attached photos of the tops, from the left:
1: original cap looks okay
2: original cap, bulged
3: new cap with a K structure on the top instead of X

[R_J]

Re: Geforce 8600 gs graphics card, failed repair

Sometimes, not always when the old cap is removed the feedthru gets pulled out and stays on the capacitors lead, when this happens the connection between the top and bottom traces can be lost.

[sofTest]

Re: Geforce 8600 gs graphics card, failed repair

If we assume that the TK caps were up to spec, AND that the Rubycon caps were genuine and so up to spec, the Rubycons would still not be a suitable replacement. You need to find caps with about same or little better ripple rating, and about same impedance as the TKs.

If you can get hold of some genuine Suncon WG (previously known as Sanyo), they would be a very good match for the TK caps, spec wise. But I advice to stay away from eBay, as there are to many fake caps for sale. Panasonic FM will also probably work, if hight is not a problem. Otherwise I would probably look for polymer caps.

[stj]

Re: Geforce 8600 gs graphics card, failed repair

the rubycons are from china, they have cropped leads.
that means they are intended to be loaded into a pick&place robot in a factory.
they may be real - and stolen/surplus from a production-line.

but yea, i would have used poly's

[xad]

Re: Geforce 8600 gs graphics card, failed repair

I've found that the original TK caps have a ripple current of 1140ma and esr of 0.036ohms while the new Rubycon cap is 945ma ripple current and 0.056ohms ESR. Would this be too much of a difference between old and new? I bought them in a rush thinking voltage and uf rating is only required having watched some youtube vids.

Also, initially when it wasn't working I took off the new caps and soldered the old TK caps back on but the graphics card would not turn on where before it would turn on in VGA mode and work but now the red VGA LED on the motherboard lit up so the card wasn't working at all, should it not have gone back to how it was before with the old capacitors soldered back on?


As for pulling the feedthroughs, that photo actually shows solder, I added more solder to remove the caps as they were a pain to remove, but just in case I checked all the removed capacitors and used a soldering iron to clean the legs up to see if I pulled anything out and it looks like I haven't, but again I could have damaged the board as the capacitors were a pain to remove and solder new ones back on.

[R_J]

Re: Geforce 8600 gs graphics card, failed repair

I suspect its more of a bad bga connection problem or the gpu finally failed? The caps you installed should be ok, I mean they should be a lot better than the original bad caps, if they are not good quality they might not last but they should be at least good for a week

[xad]

Re: Geforce 8600 gs graphics card, failed repair

Could be the GPU is dead, someone advised me to try and heat up the heatsink with a hairdryer to see if the screen comes on temporarily, tried it but still the same problem even after a CMOS clearing, red VGA_LED light and black screen.

The card is a fanless card with a big, somewhat cheap looking metal heatsink, wondering if the build up of heat over the years killed it as this model is usually sold with a fan attached and with a heatsink only, it ran very hot without a heavy load and the rare times i played games like Black Ops Zombies or GTA Vice City, i imagine it ran really hot without a fan to help, although, i'm not much of a gamer, it's mostly software like video players utilising the GPU:

(Asus Geforce en8600gt silent)

https://images10.newegg.com/NeweggIm...121-098-03.jpg




Timeline
I should probably point out the timeline of problems, initially i noticed it a few days ago with Media Player Classic where videos would play fine initially, then start corrupting and artifacting requiring me to close the video and reopen it and the same thing would happen after a while, but other video players where fine; changing MPC codec GPU settings seemed to help, instead of CUDA setting selecting DXVA-copy.

Afterwards though, the computer just started crashing on normal use, even web browsing, after getting a video card error BSOD i uninstalled the nVidia drivers and was able to start up in VGA mode (still via DVI cable), i even tied on a big case fan onto the graphics card heatsink thinking it might help it survive for a few more days at least until the new capacitors arrived, and then tried the new capacitor replacement of buldging caps and card stopped working completely, although, i think based on how problems were developing, the card was on it's way out.

[xad]

Re: Geforce 8600 gs graphics card, failed repair

Is there any point in getting the exact same TK caps and trying again? Or is the result most likely to be the same based on how the card didn't work with new or old caps.

One thing to note, maybe pointless, is that when i initially removed the four old bulged caps only to resolder them back on, i didn't solder each back to its original spot as the four were mixed together, but they were the same specification, however could it be that some of the old caps were worse than others so rearranging them caused the worsening of the card, but if i labelled their exact position maybe the card would have gone to its original state of working in basic vga mode?

[R_J]

Re: Geforce 8600 gs graphics card, failed repair

I have one of those, its a EN8600GT, It had bad caps on it also and I just used some 1000uf 6.3v from an old motherboard and it worked fine. I think I replace 8 of them.
To be honest the values are not that critical, they are used to filter the supply voltages, when they go open (bulged) they no longer filter the noise caused by the regulator ic's

[petehall347]

Re: Geforce 8600 gs graphics card, failed repair

maybe you got a short circuit or backwards caps .only you can find that .

[llonen]

Re: Geforce 8600 gs graphics card, failed repair

These cards and later were always problematic thermally, the initial failure modes you are describing are consistent with a faulty and or failing flip bga package (GPU) i just had a look for NOS stock for this and am surprised a little at their cost. Anyways if you can obtain the gpu processor and replace it that will be a more permanent solution rather than reballing or reflowing the chip. Personally if I was working on this machine for a client I would be looking for a different replacement card unless there is a very specific reason to re use this particular card.

[Behemot]

Re: Geforce 8600 gs graphics card, failed repair

If we assume that the TK caps were up to spec, AND that the Rubycon caps were genuine and so up to spec, the Rubycons would still not be a suitable replacement. You need to find caps with about same or little better ripple rating, and about same impedance as the TKs.

If you can get hold of some genuine Suncon WG (previously known as Sanyo), they would be a very good match for the TK caps, spec wise. But I advice to stay away from eBay, as there are to many fake caps for sale. Panasonic FM will also probably work, if hight is not a problem. Otherwise I would probably look for polymer caps.

Yep fleebay has too many fakes these days. I managed to get nice stock of genuine Rubycons MBZ 1000/6.3 though, years ago. Still have many available if anybody's interested.

In this case the card is most likely dead. Maybe VRM got shot because of the caps and inadequate cooling, or the GPU is bad.

[ChaosLegionnaire]

Re: Geforce 8600 gs graphics card, failed repair

maybe you got a short circuit or backwards caps .only you can find that .

this is a good point petehall made because its an asus. asus luvs doing the silkscreening for their caps reversed compared to others. for asus, the shaded side is the positive terminal! so do remember to check that before giving the card up for dead.

if it still doesnt work, its a goner which is no surprise really, since the gf 6/7/8 series are affected by the bumpgate scandal where inferior materials were used in the manufacturing of the chips from these series. this caused them to be prone to rapid failure due to heat if exposed to temperatures above 60°C. since its a passively cooled gpu, affected by bumpgate and it has a tdp of 47w which makes it almost as hot as a low power desktop cpu, its probably toast. get a better gpu from the gf9 series or later but not the geforce 400 series.

[momaka]

Re: Geforce 8600 gs graphics card, failed repair

These cards and later were always problematic thermally, the initial failure modes you are describing are consistent with a faulty and or failing flip bga package (GPU)

+1
Most likely the GPU has failed core to substrate BGA (better known as the bumpgate issue), and there's nothing to fix that short of replacing the GPU chip, which for a card like that is absolutely not worth it, unless you want practice replacing BGA chips.

As for the bulged bad caps: they were probably there for a long time - probably even long before the card failed. So most likely, you didn't do anything wrong with the recap (unless you put some caps in backwards). As R_J mentioned, even if you didn't use exact replacements, they would still be better than the bulged caps they replaced. So the video card should have worked at least for a bit. The fact that it didn't suggests there was a problem elsewhere besides the caps.

The only time bad caps can cause a video card to die like that is if they go nearly open-circuit and the buck regulators on the board damage the RAM or GPU chip. I've had that happen to two eVGA GeForce 7600 GT video cards with Sacon FZ caps (RAM died). But this situation is more rare. Most likely it is the GPU BGA that has gone bad due to the high temperature from the passive heatsink.

[Agent24]

Re: Geforce 8600 gs graphics card, failed repair

Yeah these series are not worth recapping because the GPU fails anyway.

I have an 8600GT with all polymer capacitors, still failed. It "works", but the entire screen looks like a chessboard when used with anything other than 2D graphics.

[momaka]

Re: Geforce 8600 gs graphics card, failed repair

Yeah these series are not worth recapping because the GPU fails anyway.

Not necessarily. They just need aftermarket coolers to keep the core below 60C at all times. The stock coolers are a joke. This is my solution, which is just barely enough:
https://www.badcaps.net/forum/showpo...5&postcount=33

That said, even the cooler on the 8800 GTS and GTX/Ultra are not adequate for the amount of power they dissipate (140 Watts and 170 Watts respectively). The single-slot 8800GT/9800GT cooler is even a bigger joke, incapable of keeping the GPU under 60C in idle mode, even with the fan at full blast.

[Behemot]

Re: Geforce 8600 gs graphics card, failed repair

Current attitude is to keep noise down and temps between 70-90 °C. So the fan increases speed if necessary to keep temps under these values but to stay silent also. It makes sense too, if it runs the whole time at constant temperatures, there won't be any mechanical stress from constant heating and cooling down. If you don't put it to sleep all the time anyway.

[Agent24]

Re: Geforce 8600 gs graphics card, failed repair

Not necessarily. They just need aftermarket coolers to keep the core below 60C at all times. The stock coolers are a joke. This is my solution, which is just barely enough:
https://www.badcaps.net/forum/showpo...5&postcount=33

I guess the stock coolers would be OK though, if the GPU had no defect. I also wonder if a bigger heatsink will only delay the failure since the GPU will have been at over 60 degree temperatures before that anyway.

Your solution might work well if you already had that cooler which fits the card, but to find one the right size for an 8600GT nowadays is probably not worth it - and considering how many PCI slots it will block. All that for an 8600GT, which is not that great nowadays.

I mean, it's cool that you found a solution for yourself, but for me, for example, I doubt it'd be worth it, not considering the downsides.