Re-capping eVGA GeForce 7600

[n-CHRIS-b]

As part of learning to solder, I am going to replace blown capacitors on my mom's motherboard. I've already ordered the caps kit for the MCP61PM-HM 1.0B (motherboard by ECS for HP). To assist with the learning curve, the last step before touching her MOBO is to replace blown caps on the AGP video card mentioned in the title, then testing my work in a different computer. I've done my research, including reading here, and this card was put together with only Sacon caps(!) at 1500uF 6.3V, 470uF 16V, and 1000uF 6.3V.

I respect Topcat and this site, but it was frustrating that I never got an email reply from him about what I should replace these with. So I took a chance and ordered Nichicon caps that are electrically compatible with the ones that need to be replaced. However, the caps I received are physically different from what's on the card; will this be a problem?

Also, the caps on the video card have a blue "stripe"--for lack of a better word--on the top, whose side and orientation matches the white stripe in the circles they "sit" in. I assume this means the polarity is on the blue/white side, which is somewhat confusing, because a "+" is on the other side. Do I guess correctly?

I can provide pics if you need them.

Thx for your help

P. S. I can't tell if the card is a GS or GT, partly because I threw away the box.

[mockingbird]

Re: Re-capping eVGA GeForce 7600

What series are the Nichicon caps you ordered to replace the Sacon caps?

[c_hegge]

Re: Re-capping eVGA GeForce 7600

Assuming you got the same uF and voltage as the originals, you will be fine. Topcat only sells HM, HN and HZ series, all of which are fine for this application.

[n-CHRIS-b]

Re: Re-capping eVGA GeForce 7600

What series are the Nichicon caps you ordered to replace the Sacon caps?

HN for the 470's, HN and HZ for the 1000's, and HZ for the 1500's. I couldn't tell if I needed HN or HZ for the 1000's, so I got both.

[n-CHRIS-b]

Re: Re-capping eVGA GeForce 7600

Assuming you got the same uF and voltage as the originals, you will be fine. Topcat only sells HM, HN and HZ series, all of which are fine for this application.

I went out of my way to make sure they matched. That is partly why I ask about their physical size. I don't want to damage the board.

[c_hegge]

Re: Re-capping eVGA GeForce 7600

Their physical size shouldn't be a problem. I'm assuming you are saying the diameter is different. Most cards will be screened for both 8mm and 10mm caps, and have holes for both, so you can use either. If not, you can mount them 1 or 2 mm off the PCB, which will aleviate the stress on the caps legs, seal and on the PCB pads.

[n-CHRIS-b]

Re: Re-capping eVGA GeForce 7600

Their physical size shouldn't be a problem. I'm assuming you are saying the diameter is different. Most cards will be screened for both 8mm and 10mm caps, and have holes for both, so you can use either. If not, you can mount them 1 or 2 mm off the PCB, which will aleviate the stress on the caps legs, seal and on the PCB pads.

On practice solder kits, I mounted the caps a few mm off the board while I used a heat sink. Even then, the finished product still worked. On the video card, I noticed it has holes for both the 8mm and 10mm caps, so all is not lost. lol

I actually meant the height is different, but I'm going to assume it makes no difference, since electrical ratings are electrical ratings.

Above, I think I actually answered my own question about the polarity orientation of the old caps. lol I believe I was overanalyzing about the "+" next to the circles.

[KeriJane]

Re: Re-capping eVGA GeForce 7600

Quality replacement caps are often taller than their "equivalent" cheap OEM ones.
This isn't a problem unless it's going to hit something like the case or a heatsink.
A lot of OEM caps are also too narrow for their capacity as well. Like a 10mm⌀ 4700µf/6.3v, no reputable manufacturer offers an "impossible" size. It's better to use a quality cap of lower capacity but equivalent ESR if there is no room for a larger one.

Polarity markings on the cap itself are universal- The band, stripe or mark indicates Negative (-) as does the short lead on a Radial cap.

Markings on the board are "almost" universal. Most boards are marked to indicate where Negative is, and you line up the stripe on the cap with the mark on the board.

But some manufacturers mark them opposite, with a mark for Positive (+)!
Others use a tiny + sign.

It's best to look at the board before removing the old cap and see if the markings are standard. If they're not visible, make your own marks or draw a chart.

A motherboard is a difficult soldering task. They're not just double-sided, they're multi-layered. This makes desoldering the old caps difficult as the heat is wicked away too quickly to melt the solder all the way through.

Good luck!

[n-CHRIS-b]

Re: Re-capping eVGA GeForce 7600

Quality replacement caps are often taller than their "equivalent" cheap OEM ones.
This isn't a problem unless it's going to hit something like the case or a heatsink.
A lot of OEM caps are also too narrow for their capacity as well. Like a 10mm⌀ 4700µf/6.3v, no reputable manufacturer offers an "impossible" size. It's better to use a quality cap of lower capacity but equivalent ESR if there is no room for a larger one.

Polarity markings on the cap itself are universal- The band, stripe or mark indicates Negative (-) as does the short lead on a Radial cap.

Markings on the board are "almost" universal. Most boards are marked to indicate where Negative is, and you line up the stripe on the cap with the mark on the board.

But some manufacturers mark them opposite, with a mark for Positive (+)!
Others use a tiny + sign.

It's best to look at the board before removing the old cap and see if the markings are standard. If they're not visible, make your own marks or draw a chart.

A motherboard is a difficult soldering task. They're not just double-sided, they're multi-layered. This makes desoldering the old caps difficult as the heat is wicked away too quickly to melt the solder all the way through.

Good luck!

Ok. Thanks for the pointers on polarity orientation. I know how to interpret those now.

The few times I've picked up the motherboard, I figured it would be complicated. Until working with the video card, I had never experienced soldering with such tiny holes. And without totally understanding why, I sort of knew that the motherboard would be an order of magnitude more challenging than the video card. Still, I understood that repairing the video card would be a crucial step on the way to the motherboard.

From what I've read, other people have tried--successfully--to solder new, better caps on their motherboards, with success (and with as much experience as I have lol). As with other endeavors, the learning curve is longer for me, out of worry that I'll screw it up, and because it can take a while to get my head inside what I'm doing. Again, that's the reason I choose to repair the video card first--I can learn on a smaller, less intimidating project.