Computer will not boot after 3 days of use

[arblargan]

I recently upgraded one of my computers and gave it to my wife for her photography. The specs before the upgrade were:

AMD 965 BE
8 GB DDR3 1066 MHZ RAM
ATI Radeon 5970
500 GB 7200 RPM HD
ASUS|M4A785TD-M EVO 785G RT Motherboard
OCZ 750W Power Supply

After the upgrade, I removed the 5970, 500 GB HD, and the MotherBoard. The new setup is as follows:

AMD 965 BE
8 GB DDR3 1066 MHZ RAM
Nvidia GTS 250 1GB
240 GB SSD Boot Drive
1TB 7200 RPM HD
MSI 890GXM-G65 Motherboard
OCZ 750W Power Supply

I took the video card from another computer, so the only new parts are the motherboard and the SSD.

The computer has been running flawlessly for the past 3 days, but today when my wife went to use it, the HD light was blinking like the computer was hibernating. However, nothing we did would bring it out of sleep mode. I tried pressing the power button and holding the power button, still nothing. Finally, I cycled the power switch on the power supply and tried to start the computer. Nothing. The lights come on for half a second and then nothing.

I've tried starting the computer without the video card to see if the power supply was being overloaded. Same thing. I then tried to clear the CMOS and boot up again. Still nothing. I'm wondering if my motherboard died, or what happened since it was running so good and now nothing. Any suggestions?

 

[rinval]

i would start troubleshooting by disconnecting everything from your main board except the CPU. if it powers on then i would start replacing the cables and parts starting with the ram then video etc. if the board does not power on with everything unhooked including the ram then the CPU or board is bad and being that your CPU has been working fine and stable i would vote for a bad board.

 

[rinval]

also i would try another power supply if it does not boot with everything disconnected.

 

[arblargan]

I'm 99% sure the CPU is fine. I'm just not sure if the motherboard died, or my PSU gave out. Is there a way to test with a volt meter if the PSU is working properly?

 

[rinval]

yes but with your system not staying on it will be difficult. i would still start with unplugging all but he main board to see if your get a steady power on if so they will make it alot easier to test and more accurate to see if the psu is failing/dead..

if you dont want to try that what you will need to do is disconnect your PSU from ALL connections. then in the 20-24 pin connector you will see a green wire 3rd down and a black wire beside it. (3rd and 4th pins) jumper those 2 wires. and the power supply should come on and you can test the voltages... yellow and black next to it are 12 volt red and black next to it are 5 volt. and both rails should be withing 0.5V of there respective voltages... or maybe a little higher.

keep in mind this is only testing voltage output and not amperage output so it is not 100% accurate if the PSU can support a load.

 

[arblargan]

Just wanted to update in case anyone else has similar issues to mine. I RMA'd the motherboard and just got it back today. I installed the motherboard and everything fired up first time no issues. I'm just now hoping that this one doesn't die in 3 days like the last one.