M5A78L-M/USB3 no post / no display / no beeps, no idea!

Andrew Holland

Honorable
Jan 3, 2014
1
0
10,510
Hi

Had a M5A78L-M/USB3 working ok since aug 2012. 2 months ago I replaced a noisy CIT 450w PSU with a 650w FSP Raider unit. Had a problem at that time in the board refused to POST with it. Eventually after reseating everything and moving cables around it did.

2 days ago board suddenly stops working during an undemanding windows session. refuses to restart. Clearing CMOS doesn't help, neither does removing everything except for ram/PSU and CPU. Still won't boot. Took board out of chassis and tried to start it that way, still no go.

Concluded that the board was dead and bought an identical replacement yesterday. Worked first time but then went off during BIOS setup. Worked again after clearing CMOS. Booted into windows, worked for about half hour then I powered off think it ok. This evening worked again for a similar length of time then randomly died. Or seemed. Only after clearing CMOS again would it restart. I tried it with the old CIT PSU in case it was this new PSU causing the problem. Failed to start with that. Each time I say failed to start, I mean, no video, no beeps, no POST, nothing.

Managed to get it to POST a few times with the FSP PSU but not consistently, sometimes it will, sometimes it won't.

At the moment it steadfastly refuses to do so, no matter what I do. I'm pulling my hair out. What else could be wrong here? The CPU is an FX-8150. Could there be grounding issues here? If so, what can I do to test that, since this seems so random.

Advice please!