I recently bought an asus m4a79t delux and it seemed to work fine.. That is until I powered down my freshly built computer.
When I turn this computer up sometimes all of the fans and lights come on for a fraction of a second and then turn back off and the computer fails to boot. Afterward the computer wont turn on at all, pressing the power button does nothing. I have to unplug the power until the lights on the motherboard go out (there is a lighted power and reset button on the motherboard) and then plug it back in and then it starts without even a hitch (amazing boot time by the way). Does anyone know what's wrong and if there's any way to fix it? I don't feel like spending quite a bit of gas money and making a day of RMAing this motherboard. The lights on the motherboard remain on even after the computer gets to the point where hitting the on button does nothing.
It's also worth mentioning that I'm having some problems with my front audio jacks... They're weird, it confuses which port is plugged in sometimes and sometimes it plays sound through the speakers when the headphones are plugged in and stuff like that... I only use it for the microphone, problems start when I plug the headset and microphone into it. I connected the AC97 jack instead of the HD jack to the motherboard and changed it to the right settings for that in the bios, but it didn't help.
My bios is flashed to the latest version, my computer specs are:
Asus M4A79T motherboard
8GB of Patriot DDR3 RAM @ 1333 (4 x 2GB)
An AMD Phenom 2 955 black edition (3.2Ghz quad core)
A 650W BFG PSU that's known to be good (was used in my old computer)
An 8800GT that's known to be good (was used in my old computer)
An Antec 900 case
This computer is not overclocked in any way, all settings are default (aside from the audio settings which were adjusted for standard definition audio).
A short? have you tried running breadboarded out of the case. If this works ok leave it out try the headphone/microphone, still no problems?
Visually check the mounting points on base, compare these to bottom of motherboard looking for any pins that might short or arc to mounts, insultate with masking tape, the screw will still provide the neccessary ground. Same thing with backing plate sometimes the grounding legs get bent and slide under the board.