Dead board with no obvious signs

**Gianni** · 10-02-2008, 04:25 PM

Re: Dead board with no obvious signs

I have not seen something strange except for the blue heatsink near memory slots, have you cut it?

Reducing heatsink increase the device temperature and maybe this bring it to fail in the long run.
If you connect the PSU and try to start the MOBO, does the CPU Fan work?
Can you feel if something is overheating on the MOBO?

I see some Nichicon cap and if I'm not wrong there have been some faulty production but I can't remeber the years.

I have no suggestion, you have already done what I would do, maybe someone else here can help you.
Gianni

**rawgerz** · 10-02-2008, 05:12 PM

Re: Dead board with no obvious signs

It's not the stock heat sink.
I had to clip some pins to make room for the newer video card, but it never went over 90F. CPU fan didn't die either.

**zandrax** · 10-03-2008, 01:10 PM

Re: Dead board with no obvious signs

The K8NXP-SLI is a late 2004 motherboard, so it could employ bad Nichicon HN or HM caps (bad ones were manicatured from 2002 to 2004): I don't see any bulged cap anyway.
For starter I'd clear the cmos (detach the power cord and remove the battery for about 10 minutes) and boot the minimal config: mobo, cpu, 1 stick of ram, videocard (maybe a cheap entry level one, just to avoid power issues) and psu. If it still doesn't post, check the chipset (the one under the cut blue heatsink): the nForce 4 has a serious heat problem which can be exacerbated if the heatsink doesn't dissipate heat enough (because e.g. the graphic card is too long and blocks air cooling).
BTW, can you list all components?

Zandrax

**PCBONEZ** · 10-03-2008, 02:40 PM

Re: Dead board with no obvious signs

Some Nichicon HN and HM series caps made between 2002 and 2004 were defective, though they usually bloat.

I also see a chemicon KZG.
I've had those fail with no visible signs of a problem.

.

**rawgerz** · 10-03-2008, 03:26 PM

Re: Dead board with no obvious signs

I already tried clearing the cmos the day it died. I left the battery out all night.
I also took all the heatsinks off for to check for any scorch marks, nothing.

When it went dead it had
2x1GB and 2x512MB of corsair value ram, Opteron 145/8?, 8800GTS, and a 1yr old PC power 610W. It has to be the board because the same PSU, VGA, DVD, HDD, and PCI cards are in the new machine.

I even tried my old 6600GT card and another 410W PS in it after leaving the battery out, and no ram at all. Just blank screens with no beeps. Fans still worked but that was it.
I was under the impression that bad caps would give symptoms over time, not just up and die?
This board was rock solid up till then. Even if it's repairable I'm still a bit leery on doing so. If the RAM is no good I wouldn't bother any further since regular DDR hasn't gotten any cheaper sadly. But at this point I'm only looking for the cause.

It's been replaced by a EP45-DS3L
http://www.newegg.com/Product/Produc...82E16813128345
I just hope this one is as good as they imply..

**PCBONEZ** · 10-04-2008, 03:04 AM

Re: Dead board with no obvious signs

Caps aren't all the same, they don't all fail for the same reason, and are all subject to differing conditions,,, There are many different failure modes for capacitors.

I have twice had KZG problems where the system worked fine one day and then simply wouldn't boot the next morning. I know it was the KZG because that's all I replaced.

.

**kc8adu** · 10-04-2008, 08:45 AM

Re: Dead board with no obvious signs

even if the ram is bad corsair has a lifetime warrenty.
and i had a board that looked fine cap wise that would not post.had a shorted nichicon hm on vcore.
vrm would not run into that short.
time to see what is not running.
so many things can cause no post.no clock,vcore,vdimm,whacked bios,ect.

**bgavin** · 10-04-2008, 10:49 AM

Re: Dead board with no obvious signs

I have a Gateway board that is DOA after recapping. It is in the winter projects bin for re-evaluation. I used all Rubycon MCZ but it is solid DOA. The VRM sings quietly so I know I have a cap problem.

I didn't ESR test each cap prior to replacement. Then again, I didn't have an ESR meter, either. Over the winter, I will build my ESR meter kit, and see if I can correct this board.

OP, if your board is valuable to you, recap everything from 470uF and up with premium caps. Or, can do it in sections. Start with VRM, then memory, then the field caps.

Dead board with no obvious signs

Dead board with no obvious signs

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