evga 680i sli recapping

[mavros_pit]

Hello everybody. I have an issue with broken bulged caps with my evga 680i sli mobo and i could need any help.

My motherboard is in attachment and i need recapping of the following caps :

1. 2x rubys MFZ 6.3v 2700uf 10mm diameter (light green rectangle)
2. 4x rubys MCZ 16v 1800uf 10mm diameter (red circles)
3. 4x samxon GC 6.3v 1500uf (light blue rectangle)
(i already read about high ripple and very low esr on both rubys)

I think that something went wrong with temperature because few weeks earlier my northbridge cooler stopped. So this is probably the reason of bulging.

Nowadays there are not compatible electrolytics for the rubys (neither in digikey, mouser or here) so i can guess polys is what i have to place, but i dont know what series or capacitance.

Any help would be appreciated.

[mavros_pit]

Re: evga 680i sli recapping

Are the following polys acceptable for my recapping?

for the MCZ rubys:
https://gr.mouser.com/ProductDetail/...CsuGaUyQ%3d%3d

i cant find some suitable for the other rubys...

[momaka]

Re: evga 680i sli recapping

Are the following polys acceptable for my recapping?

for the MCZ rubys:
https://gr.mouser.com/ProductDetail/...CsuGaUyQ%3d%3d

More than acceptable.

With polymers, typically you can go about half of the capacitance, if using polymers in place of electrolytics, for the caps that filter power going to the CPU.

But from experience and observation on other motherboards, I can tell you for sure that even 16V, 470 uF polymer caps would be okay to use in place of those MCZ caps you circled in red. Nichicon (series LF, RR7, RR5, RE7, RE5, among others) or United Chemicon (PSA, PSC, and PSG) should likely all meet or exceed the ESR and ripple current specs of the MCZ caps you currently have.

As for the Rubycon MFZ... they are pretty much equivalent to the Rubycon MCZ series according to old posts I've read here, so they are directly replaceable with whatever is compatible with MCZ. That said, for those 6.3V, 2700 uF MFZ caps, you can use 1200-1800 uF polymers. Based on their location, I *think* they are for filtering power going to the Northbridge. But because I can't be sure if they are on the high-side (typically 5V rail for the Northbridge for most motherboards), you should use 6.3V rated polymers.

Alternatively, you can use Nichicon HN or HZ caps to replace those bulged MCZ and MFZ caps. For the 2700 uF MFZ, 2200 uF Nichicon HZ is fine. They are often used interchangeably on Xbox 360 motherboards and have very similar specs. The slight drop in capacitance is not a big deal.

Last but not least, the 6.3V, 1800 uF Samxon GC caps....
Again, I'm not sure if (and which) any of these are connected to the low-side and high-side of the Northbrdige filter, so go with 6.3V polymers again. 820-1200 uF should do fine. Or Nichicon HN/HZ series again. Whatever you can find available.

I think that something went wrong with temperature because few weeks earlier my northbridge cooler stopped. So this is probably the reason of bulging.

If that has happened, do not use the motherboard at all until you recap it and fix the fan. The nVidia nForce 650i, 680i, 750i, and 780i chipsets all become extremely failure-prone when exposed to excess heat. So make sure that Northbridge fan is running well. Maybe even consider upgrading the fan to a bigger one with more pressure and airflow.

And make sure your case gets very good ventilation too. For those Rubycon MCZ and MFZ caps to bulged like they did, there was probably significant heat build-up near the Northbridge and CPU area. Once the board is fixed and fans running, open your PC after a normal use session and touch some of the components in that area. If anything burns your hand, you may want to add more ventilation to your case, or simply just have a fan blowing air inside the case to keep components cool. The Northbridge temperature should also be kept under 60°C at all times if you want that board to last (and 55°C if you certainly want to be on the safe side).