PC Failed to power on

[WhiteZero]

PSU: SeaSonic SSR-650RM
Motherboard: Asus Z87-PLUS

Built this new rig in January of this year. Been running like a champ. Came home the other day from work to find my PC was off (I leave it on pretty much 24/7). Press the power button, power light blinks and goes out, blinks and goes out again, nothing. Unplugged it and plugged back in, tried different outlets, etc, no difference.

Took off the cover, mobo power light is on as normal. Pressing the power button, it looks like the fans kick on for a brief moment, only moving an inch, then stops. Case power button and mobo power button do the same thing. So I unplug all power connection except for the mobo, attempt to power on, same issue. Unplugged the 24-pin ATX power cable and plug it back in to make sure it's seated properly, same issue.

So I short the green and black wires on the 24-pin ATX power cable to jump start the PSU, and the PSU fan actually comes on! So I plug everything back in as normal, PC was powering up fine after that.

4 days later, I'm at work and I see that my PC is offline again. So I'm assuming the same thing has happened, will verify when I get home. I'm really torn on if this is the PSU or mobo. More than likely seems like the PSU to me.

 

[Armenius]

Did you check the 4/6/8-pin ATX +12V cable for the CPU? I would also check that the CPU HSF is secure and seated properly. Putting on some fresh thermal compound also couldn't hurt.

 

[WhiteZero]

Yeah I've checked the CPU power as well. I don't think its overheating, because when I get into BIOS or the desktop the temps are fine.

So I got home today and its having a similar problem now. If I leave it unplugged for a few minutes I can get a minute of it working, but then it turns back off. So it really seems like PSU now.

EDIT: Did the jump start check with nothing else plugged in. PSU stays on for a minute then goes out. Going to RMA.