I've got an intermittant issue with my motherboard (ga-ma785gt-ud3h with a Athlon II X4 630 chip). It has been working fine for months then suddenly last night wouldn't work. My power supply has a light on the back to indicate it's running, and this wasn't lighting up. If I disconnected it and reconnected it several seconds later, I'd get a light for a few seconds then it would disappear.
Thinking the power supply was the problem I swapped it with a known good one. It booted no problems so I bought a new one today. I even swapped to a new PC case at the same time (which hopefully rules out a shorting power switch)
After using the PC for a couple of hours it just shut off. The power supply light and fan were working but nothing from the PC. Reconnecting the power I could get it to start but it would power off after approximately 1-2 seconds. I suspected a CPU overheat but couldn't get it to boot long enough to see the temps in the BIOS.
I stripped everything from the motherboard and powered by shorting the pins and could get it to start. I reconnected everything and again got it to start. I've installed easy tune 6 since it restarted and have been watching the core temp, but it's hovered almost permanently around 33 degrees C/40 degrees system temp (105 and 91 degrees F)
So at this point I don't know if I have a faulty board or not and can't find any diagnostic tools or way to retrieve any diagnostic logs from the MB.
Any thoughts would be appreciated!!!
(I've gone through the troubleshooting steps in the sticky - everything is seated correctly and plugged in. The only thing I haven't done is breadboarding, but as it's been running now for an hour, I can't see that it would lend any benefit)
I'll check, but I think the motherboard is out of warranty.
I am able to get it to start after the computer crashes/dies by shorting the start pins on the board - otherwise it's like the start button is stuck on as it tries to start automatically once the power is reconnected.
After the last restart it had to load the BIOS from a backup copy too.
I had a similar issue once. Had to remove the plastic front bezel plate to fix a loose portion of the power switch. Be careful; last time I did this I broke off the reset button wire. I would still breadboard the motherboard; check under and around it for loose wires and screws underneath, be sure the backplate is square. Also be sure no pressure is on any of the power supply wiring. Bent wires on the connectors could also cause a short or bad contact with the board.
Thanks o1die. I'm not convinced it's a power button issue as I swapped cases mid issue (I had been planning to do it for a while anyway as my original case was a bit cramped) - it's unlikely that 2 cases have dodgy on switches. Apparently the restoring BIOS from backup copy thing is related to holding the power switch on though.
As a first step I'm going to use the reset button as the start button. If it's not stable for the next few days I'll see where I go from there. Unfortunately as it last worked for a few hours and I have small kids it's not easy to breadboard, but I'll cross that bridge when I come to it.