A8N-SLI Premium full recap gone bad

[nmalinoski]

I spent the past couple days working on a full recap of this A8N-SLI Premium v1.02. The board only had a few bad caps when I started, and it worked fine, but I figured I'd replace everything rather than have to repeatedly pull the board every time one goes bad.

I made a cheat sheet with locations and capacitor info, then ordered caps from DigiKey; everything Panasonic except for the 10uF caps, which are Nichicon.

When I finally got everything back together (Just the board, PSU, and PCI video card hooked to a monitor), the board wouldn't POST. The board gets power, but, when I push the power button, the CPU fan would spin, but then stop about half a second later. Pressing the power button again immediately after didn't have any effect. I tried again later, and several caps (specifically PCE1, PCE4, PCE10, and PCE9) exploded in sequence like firecrackers before I could flip the PSU power off. In addition, CE8 is now bulging.

I'm not entirely sure what I did wrong (aside from powering the board again). I used a desoldering gun to make easy work of the caps, and I made sure to install every cap in the correct orientation. Could I have damaged any components heating the board with either my iron or my desoldering gun? Did I buy the wrong replacement caps? What am I missing?

[petehall347]

Re: A8N-SLI Premium full recap gone bad

missing pictures .

[nmalinoski]

Re: A8N-SLI Premium full recap gone bad

Oops. Photos here: https://drive.google.com/open?id=1NE...fOIWjZWEHNYeem

[Wester547]

Re: A8N-SLI Premium full recap gone bad

So, it looks as though you installed the replacement caps backwards (several have vented). On ASUS boards, the shaded side of the polarity circle is positive rather than negative.

[nmalinoski]

Re: A8N-SLI Premium full recap gone bad

Thank you for pointing that out. Hopefully it just boots after I get replacement replacements and get everything swapped around.

Is this just something Asus does to be different? My understanding was that the shaded portions correspond to negative, and thus the stripe.

[Sparkey55]

Re: A8N-SLI Premium full recap gone bad

Oh No! Possibly another ASUS motherboard that wont post and for parts only on Ebay again.

[nmalinoski]

Re: A8N-SLI Premium full recap gone bad

Oh No! Possibly another ASUS motherboard that wont post and for parts only on Ebay again.

Even if I did irreparably harm this board, I wouldn't try to pawn it off on someone on eBay.

After reorienting the good caps and replacing the bad ones, the board boots fine, and it survived 9 passes of memtest overnight.

[quicknick]

Re: A8N-SLI Premium full recap gone bad

I might be wrong, but I wouldn't trust any cap that was reverse-biased for any length of time.

[momaka]

Re: A8N-SLI Premium full recap gone bad

So, it looks as though you installed the replacement caps backwards (several have vented). On ASUS boards, the shaded side of the polarity circle is positive rather than negative.

Yup!

Older ASUS-made AsRock boards, as well as Pegatron are like that too.

Now the funny thing is, I have recapped so many ASUS boards in the past that sometimes I almost install caps "in backwards" on normal boards.

Even if I did irreparably harm this board, I wouldn't try to pawn it off on someone on eBay.

Well, as long as you give it a proper description of what happened, someone might actually buy it. (hint: someone like me. I've actually bought a fair share of broken PC stuff on eBay. Some of it was a big gamble that I was almost certain that wouldn't work - and most of which didn't. But others times, the seller(s) described the items honestly and what was done to them, so a good deal of these I was able to get working again... or at least asses if they are worth my time or not to try to repair. Some items I indeed only got for parts use and not to repair.)

After reorienting the good caps and replacing the bad ones, the board boots fine, and it survived 9 passes of memtest overnight.

YAY!
Good to hear its working again!

I might be wrong, but I wouldn't trust any cap that was reverse-biased for any length of time.

I agree. Though it depends on where the cap was located. In any case, I'd replace all caps again on the important rails, just to make sure.