AU31 Motherboard with Bestec 250W PSU is toast

[masteroftime]

I am attempting to repair a friends computer, Emachines model: T2865. The motherboard is an AU31 connected to a Bestec 250W powersupply and an AMD athlon 2800 processor. The computer would randomly shut down and power off during use, and one day just died. Now it does not post boot, the CPU and PSU fan spins immediatly when power is applied and the machine wont respond to the power button on the front whatsoever. I read a couple posts here where people have had the same problem, but didn't know what they did to resolve it. Any ideas to get started?

[kc8adu]

Re: AU31 Motherboard with Bestec 250W PSU is toast

try another psu and quarentine the old one.
unfortunately the bestec probably already killed the board.

[davmax]

Re: AU31 Motherboard with Bestec 250W PSU is toast

Have you looked at motherboard and inside PSU for bad caps?
Have you checked the bios backup battery? Check for low voltage and remove it for a minute or two then replace. The latter will refresh the bios that may be corrupted and prevent boot.

[zandrax]

Re: AU31 Motherboard with Bestec 250W PSU is toast

The latter will refresh the bios that may be corrupted and prevent boot.

Corrupted cmos, I hope
Don't worry, I wrote the same thing about two weeks ago ...

Zandrax

[Lance Thornton]

Re: AU31 Motherboard with Bestec 250W PSU is toast

I've actually seen several of these boards killed by the bestec's. Look very carefully at the southbridge and check for scorch marks or divots. Good Luck!

[linuxguru]

Re: AU31 Motherboard with Bestec 250W PSU is toast

Those DFI boards were pretty good, and if it has survived, you should probably recap it if it has OSTs or similar crap caps. The Bestec PSUs are known mobo killers - I'd probably recap and reserve them for non-critical use on legacy low-power systems (P2/P3 etc.), definitely not heavy-duty, heavy-load use.

[kc8adu]

Re: AU31 Motherboard with Bestec 250W PSU is toast

the au31 is a fic

[masteroftime]

Re: AU31 Motherboard with Bestec 250W PSU is toast

yes it is a fic. i tried a new power supply with no sucess. also tried clearing the CMOS like mentioned above...nothing. I don't see any bulging caps or anything physically out of the ordinary. I think im going to try recapping the whole thing, i have nothing to loose. just wondering if theres a specific Cap that is known to go first or something else i should check for this model.

[davmax]

Re: AU31 Motherboard with Bestec 250W PSU is toast

Last chance maybe. I recommended removing the battery to reset bios, this does not always work because a capacitor is used to hold charge whilst changing the battery. The only sure way to reset the bios is to locate the bios reset jumper. It has three pins and usually labelled CMOS. There are two possibilities 1.that the jumper has been left in the wrong position and 2. bios is still corrupted. First with power off move the jumper to the alternate position for about 15 sec then move back and apply power to check for change. If nothing remove power and move jumper to the 15 sec position and try power again.

DO you have a mainboard manual? this should indicate CMOS jumper and the correct running position.

[davmax]

Re: AU31 Motherboard with Bestec 250W PSU is toast

Found AU31 manual link: http://www.lurkhere.com/~nicefiles/AU31_manual.pdfThe CMOS reset is near the battery.

[Spacedye69]

Re: AU31 Motherboard with Bestec 250W PSU is toast

Ditto on looking at the southbridge chip very carefully. Look for a dent, bubble, or black spot.