Computer froze after 30 mins and won't boot into BIOS

[gsferriss]

About a month ago, my computer froze and failed to boot into BIOS (No POST); No display; I tried stripping the system of all but the necessary parts in order to boot, put in a new CPU, tried a new video card, tried each of my 4 sticks of RAM in every combination of every slot, and even a new CMOS battery; No dice.

I concluded that the problem was the motherboard, and recently bought a new one from newegg.

I spent a good hour or so taking out the old motherboard, and putting the new one in, documenting every cable and card I unplugged and worked backward using the same list when I put the hardware into the new motherboard.

I turn on the computer and it boots fine! I inserted the motherboard driver disk and installed everything necessary for the computer to run. After a reboot, the computer worked fine in my monitor's native resolution (this means the graphics card drivers installed successfully).

After 30 minutes, the screen turns black, and all audio coming through my headphones ceases; The same thing that happened with the old motherboard. Cursing to myself with my fingers crossed, I power the system off and wait a few seconds before powering it back on.

No boot. Can't get into BIOS; same problem. Here are the things I have troubleshooted with the new board:

I replaced the 4 2GB sticks of memory with a single 8GB stick. Nothing.
I cleared the thermal paste from my CPU and reapplied a fair amount of paste (I felt there was too much, and wanted to see if the metal wasn't getting enough contact). Nothing.
I replaced my Phenom II with an the Athlon II 170u that I'm using in the spare I'm typing this from, applying what I thought was a fair amount of paste. Nothing.

The only thing I haven't ruled out with the new board is the video card, which I will hopefully be able to do tomorrow (spare system is integrated, and neither of the new boards have integrated graphics to troubleshoot with), but thought I'd post here incase there is anything I'm missing. My hardware specs are as follows:

Old Board: ASUS M4A79T Deluxe http://www.newegg.com/Product/Product.aspx?Item=N82E16813131363
New Board: ASRock 970 EXTREME3 AM3+ http://www.newegg.com/Product/Product.aspx?Item=N82E16813157280&nm_mc=TEMC-RMA-Approvel&cm_mmc=TEMC-RMA-Approvel-_-Content-_-text-_-

AMD Phenom II X4 965 Black http://www.newegg.com/Product/Product.aspx?Item=N82E16819103727

Mushkin DDR3 1600 Black (4 x 2GB) RAM

Radeon HD 5850 (Sapphire Card) Video Card


The parts are all about 3 years old...
One thing I should note is that the new motherboard I got seems to get a lot of DOAs by users... I don't think I got a faulty board though because it did boot twice... Then the same thing that happened with my old board happened to it.

Another thing I should note: The spare system I am using is a prebuilt and comes with no PCI-e slots to test the video card in my main system. Just thought I should say something before it gets suggested.

 

[Outlander_04]

Do you have another power supply you can try?

 

[gsferriss]

Not on hand. I guess it is the only thing I haven't checked thus far, but I won't be able to get my hands on one until later on. I'll post back in this thread when I do.

 

[gsferriss]

Okay so I got a hold of a generic 300W power supply as well as an older NVIDIA card (not sure of the model). The system still won't POST with the old card/300W supply but I'm not sure if 300W is enough for my rig. I would think I'd at least POST, but there may be another problem here.

One thing I noticed with my old PSU is that the fan will not run when it is plugged in and powered on with the system. Could this have caused any damage to any of the other parts in computer? Possibly my motherboard(s)? I'm stumped as to why the system won't boot with the new 300W PSU when the old PSU seems to be the culprit. Any help is appreciated.

EDIT: The old card may not work. I got it from a friend who hasnt used it in years (the replacement PSU too).
I will try running my 5850 with the 300W, but I doubt it will work. That thing is a beast and sucks a lot of power. Hopefully the system will at least POST, since the graphics card doesn't need a lot of power idling. Idk, I'll post back with results.

 

[gsferriss]

Shameless bump. Wondering if broken PSU may have damaged other parts in the system