Time to replace the PS?

[Jovec]

The setup:

Computer has been working without issue. This morning the computer appeared on (lights/fans) but would not wake-up monitor. Turned the computer off via power button, then system would not turn on.

Tried manually jumping power switch at mobo pins, even though switch should be good as it turned the system off. Clear CMOS. Pulled battery. Hooked up another PS at motherboard 24 pin ATX and 8 pin ATX_12v only and turned on computer. It powered up. Shut it off, hooked up original power supply, and it is working.

PS is a Seasonic x650 Gold, about 20 months old. Obviously I'm worried about the PS taking out the mobo and CPU, so I'm debating if I should just mark this one as bad and buy another. Also curious as to what caused this.

I am also debating if I should try stress testing this PS under P95 or similar.

Thoughts? Ideas? Suggestions?

Edit:

Just put the computer into sleep and resumed it. Upon resume, Windows installed the Via 1394 firewire driver, which I have set to disabled in the BIOS (just confirmed it is disabled). The new CMOS battery was just one I had laying around. I'll probably need to buy a new battery to be sure, but even still the computer and BIOS should be drawing power from the PS while under sleep. Mother board issues instead?

 

[Jovec]

After previously having disabled sleep and using the computer with no problems, I just forced the computer into sleep as a test. It did not resume. It appeared to be powering up for 2-3 seconds and then shut off. Toggle the PS power switch to off for about 10 seconds and the computer booted up without issue. Running P95 small FFTs now, with no immediate issues. I will let it run for awhile.

I can't imagine it is too different for a PS to boot cold or resume from sleep, so I'm leaning towards the mobo.