NEED HELP! pc wont boot

So i woke up this morning with my GF telling me her computer wont turn on. I was the one who built it, and it has been running fine since. I hit the power button, and all the lights come on, the fans start spinning. yet it doesnt boot to the bios let alone post to windows. When i tried to reset it i found out that it wont power down through the power or reset buttons. i have to flip the switch on the psu to turn it off (i know thats bad but its either that or unplug it). I've tried clearing the CMOS. the system is not overclocked at all aside from the factory OC on the gpu. Also something i just noticed while writing this is that the fan lights on the case light up, but not the power indicator light even though all the fans are spinning and power is clearly moving through the system.


Does it beep?

Bad PSU. Pick up a $20 power supply tester to know for sure. If you don't have one, start but unplugging everything except for mobo, cpu, ram, and video. Take every other component out of the equation. Remove any USB devices as well. Gradually add components from there, assuming it's not the PSU and it starts booting again.

yeah it turns out it was the PSU. i swapped in the one from my system and it worked. though now i wind up with a few options for fixing this. first is the PSU in question is still under warranty so i can RMA it for a direct replacement. however im using a 750watt PSU for my tw0 g1 gaming 980s and have been considering selling them for two of the g1 gaming 980TIs; which would require a larger PSU. so im thinking give my gf my 750watt and order a new 850watt for myself. then RMA the dead PSU to put into a hobby build. thoughts?