Computer wont turn on!! Not the PSU!

[chnchapters]

I just recently built a new computer and it was running perfectly.
AMD Phenom 2 x4 970 Black edition
Gigabyte 78LMT-S2P Motherboard matx
500w power supply (cheap off brand)
$19.99 cheap case
8gb ddr3 ram (4gb x2)
Raedon HD 6750 1gb graphics card
500gb HDD pulled from a new compaq PC

Then during gameplay and randomly the computer would just turn off and not start back up for awhile. I didn't want to spend time figuring out the problem and just wanted my new computer to work so I went out and bought a new graphics card and PSU...

So now I have a 600w decent psu (that i know works)
and a Nvidia Geforce GTX 550 TI 1 gb graphics card

The computer worked fine for a while then I picked it up and moved it to a diofferent house. Now it wont turn on. After trying to start it a bunch of times it finally booted up but then shut off 5 min later like we lost power.
Now nothing happens, the psu fan doesnt spin, no lights come on, its just as the PC has no power coming from the wall.

I swapped PSUs and cases still nothing. What could this be? Im going crazy? Did my motherboard die somehow?

 

[sosofm]

You have power on the wall ? Connect you pc in another power from the wall. It's not normal the psu fan doesnt spin, try another power cable.

 

[inzone]

Have you rechecked all the power connectors on the motherboard to make sure they are seated all the way in. It does sound like there is something loose and it is definetly tied to the power supply if just moving it causes it to not turn on.

 

[chnchapters]

Its not the powersupply because I swapped it out with a new one and it still doesnt work.

I changed the cord and tried another wall socket, there is power.

I tried starting it with just the cpu, one stick of ram, still nothing

I rechecked all the connections because I took the pc completley apart and rebuilt it.

 

[chnchapters]

Does anyone know if it is the mobo? I want to go out and buy something to fix this right now

 

[ko888]

Does anyone know if it is the mobo? I want to go out and buy something to fix this right now

Motherboards do fail.

I don't know if your GA-78LMT-S2P has a +5VSB indicator LED to indicate if it is still receiving power from the power supply.

 

[vegettonox]

Unfortunately the motherboard and cpu can be very hard to diagnose as faults with either will show most of the same symptoms, have you tried resetting the cmos via jumper 5 ? If you do replace a component I would first replace the motherboard as its most likely to fail before the cpu.

 

[Doctor_Den]

Sounds like something shorted. Could be something as simple a the heat sink not being seated properly. If it has shorted that could also mean your PSU has blown, so first step would be to test your psu with a working computer.