Shuttle XPC SN68SG2 Badcaps

[JonPruett]

I just successfully replaced two 1800uf caps that blew on my Shuttle XPC SN68SG2 motherboard. This morning the system wouldn't start - after replacing the caps it works perfectly.

Thanks for all the info and advice here!

[c_hegge]

Re: Shuttle XPC SN68SG2 Badcaps

You only replaced the two bulged ones? NEVER do that. always replace all of the caps, bulged or not for 2 reasons:

1. Even if the other caps haven't failed yet, they aren't far off and
2. It is common for caps to fail with no visible signs

[japlytic]

Re: Shuttle XPC SN68SG2 Badcaps

2. It is common for caps to fail with no visible signs

I've seen that happen too. Depending on the colour of the capacitor sleeve, it may become discoloured or even shrink under the right circumstances.

[AdamC]

Re: Shuttle XPC SN68SG2 Badcaps

So, I have an SN68SG2 like the original poster. When I first got the board it wouldn't power up with the first power on but after the 4 second hard power off it would run like a champ. But, it never would run with full memory speed. Now under a load it will lock hard. I've got 33 standard caps and 13 polymer caps. The standard caps run from 1800uF to 10uF and the polymers run from 820uF to 330uF.

My question is this: Do I really need to replace all of them or should I just replace the bigger capacatance capacitors (4 1500uF, 9 1000uF, and 2 1800uF)? The smaller standard caps are 10 16v 100uF and 8 2.5v 10uF. The polymer caps are 10 - 2.5v 820uF and 3 16v 330uF.

Thanks for your help in advance.

- Adam

[Colt45ws]

Re: Shuttle XPC SN68SG2 Badcaps

I would replace all the standard ones 470uf and up. The poly caps are probably around the CPU, correct? I would leave those alone. Also check the supply.

[AdamC]

Re: Shuttle XPC SN68SG2 Badcaps

Just to recap (pardon the pun), I did replace all the capacitors that were 470 and up (with one exception, I'll get to that at the end).

Prior to the cap replacement I could not get my memory to run at the rated DDR2-800 speed and after it runs at the full rated speed. Also, during periods of high disk+cpu+memory operations it would lock up and require a hard reboot (StarCraft2 campaign loading process). Now, it's rock solid and has not crashed once.

I did not replace the capacitor between the PCI and PCIE slot because I couldn't completely read the label. Could it be a 470uF 16v capacitor?

[tweak]

Re: Shuttle XPC SN68SG2 Badcaps

Hey guys, just signed up here to post that I successfully replaced two bulging 1800uf caps on my Shuttle SN68SG2. Got a pair of Nichicon caps from local electronics store for buck apiece. Practiced on an old motherboard using Hakko 936 then did the deed on the real thing. Feels damn good when the thing posted and booted right up.

Before:
The system had suddenly started to shutdown 3 sec after power on when a pcix graphics card was installed. It would boot with the integrated video, but I need the card for hdmi. I thought it was flex psu since it did boot with a ATX desktop psu. By chance, I stumbled on a shuttle forums thread saying to check the caps and sure enough they were bulging.

After:
Running stock Ubuntu w/XBMC. System seems stable for now. I may go back and recap the rest of the board if any more bulges show or any weird instabilities happen. I did overheat my hakko tip (it turned blue) but that's small price to pay for successful repair.

Also I'm not sure if the Nichicon caps I used are "Ultra Low ESR" as I'm just now reading here on the forums that there's a difference between the off generic the shelf Radio Shack vs. PC motherboard caps.

[minusp]

Re: Shuttle XPC SN68SG2 Badcaps

Another SN68SG2 here... did the bad thing a few years ago and just replaced the two 1800uf caps, they have gone all bulgy and fail-like again. Is there a list of the caps that would have been in the kit available?

[momaka]

Re: Shuttle XPC SN68SG2 Badcaps

Another SN68SG2 here... did the bad thing a few years ago and just replaced the two 1800uf caps, they have gone all bulgy and fail-like again. Is there a list of the caps that would have been in the kit available?

The kit for these PCs... replace all OST caps in the computer that are 220 uF and up. These machines run hot and often cook the caps. Open your PSU as well and check it. May have bad caps in there as well.

[chowder]

Re: Shuttle XPC SN68SG2 Badcaps

Open your PSU as well and check it. May have bad caps in there as well.

Definitely this, particularly if you've replaced the caps before and the new ones bulge too. Some Shuttles actually run cooler than you'd expect, but the PSUs are all cramped little heat boxes. Throw in some CapXon or similar caps, and things are going to go wrong