Asus Motherboard or CPU

LunaEros

Reputable
May 25, 2015
14
0
4,510
Have a system with an Asus M4A785-M MB and an AMD cpu. Forget which CPU at moment.

Was watching a movie on it when the movie froze. I killed it and started the movie again and it froze again. So I tried opening task manager to see if there was a process hogging a lot of memory or something and it acted like it was going to start (Hourglass) but never did after 3-4 minutes. Got irritated and manually turned PS switch off. Waited a minute and turned switch back on, but it was dead. No lights no fan no nothing.
Opened up the case to clean it out all the caked up dust. CPU heat sink was fairly hot but I could keep my finger on it. Let it cool for an hour. Pulled heat sink and cleaned it cleaned top of cpu put new compound on it. Still nothing, noticed the SB_PWR led on the board flashes dimly when PS is on but nothing when it's off. Checked PS and all voltage are correct except the -12v line which is reading -11.5v but I figure that's probably not it? Plugged everything back. Nothing. Pulled cables to drives and took memory out. Nothing. Took Bios battery out cleaned it tested +3plus volts. Put it back. Nothing.
Haven't pulled the board off to che3ck underneath because I think the odds of something under it shorting is nil.
So unless the -11.5v instead of -12v causing it then I'm down to motherboard or cpu went bad.
Is there any way to tell which? I don't have another board or cpu or PS to try. Only a voltmeter and the led on the board.

Any help ASAP would be greatly appreciated.
 

LunaEros

Reputable
May 25, 2015
14
0
4,510
I pulled the supply out and tested each pin. Every one was dead on except for the -12v which only reads -11.5v but considering the mb led seems to be indicating that there's something wrong onboard or with the +5v supply to it I didn't think a ½v low on the -12v pin would be a problem.