Gaming system trouble! Press F1 to continue, Bad power supply?

[Juan Juarez Baldizon]

So, my system has been working great until recently I get press F1 to continue whenever I shutdown the pc, I switched the CMOS battery and updated my bios, but when I'm in sleep mode (which is usually what its in) everything is fine! I overclock the snot out of my 2500k (4.8 on h100) and get stable performance. But the strange thing is now when I shut down the computer (not sleep mode) the front case button doesn't work to turn on the power, I see inside the case the graphics card and motherboard have power, (lights are on but nothing powers on) and what I discovered is when I remove the power supply cable and plug it back in the system powers on the first time I press the case button. Some help would be greatly appreciated this system is my baby haha but replacing something isn't out of the question, Motherboard or powersupply, just got to do what is necessary, Specs bellow:
Asus p8z68 v-pro/Gen 3, Windows 7 64
16gb @ 1600mhz corsair vengeance ram, i5 2500k, Asus 680 gtx direct cu II, Coolermaster silent pro 800W powersupply, Coolermaster cm storm trooper case.

 

[bignastyid]

Sounds like a capacitor in the PSU has failed(it is a cooler master and they are notorious for bad power supplies), but it could be a motherboard problem aswell. You wouldnt happen to have access to another PSU to test with would you?

 

[False_Dmitry_II]

I don't think I would go as far as to say they are notorious for that.

I'm still running an 80+ 650 watt coolermaster from quite a long time ago and it's still working fine, meanwhile I just saw about a month ago a corsair one make a UPS scream bloody murder. Not sure, but the UPS may have saved the actual stuff, because that still works.

That said, I'd definitely test it and see if it is still under warranty.