[SOLVED] Computer won't turn back on after turning off

[heyhyrule]

My friend texted me with this, and we've troubleshooted as much as we could and gone through all the guides, and now have no idea where to go.
This is what he said

I tried to turn off the pc, and the monitors shut off like normal but the pc stayed on, so I unplugged it and replugged it back in. Now it wont turn on.

when pressing the power button, it does nothing, and there are no lights in the case. His motherboard doesn't have any indicator lights either, and wasnt making any beeps.
This is the first problem we've had with it since he got it in june.

SPECS:
ryzen 5 2600
8gb ddr4
gtx 1660
500gb ssd + seagate 2tb hdd
it has a 550w psu
and we don't know what the motherboard is, he thinks its either and asus or acer based from the splash screen.

 

[JohnBonhamsGhost]

try a different power supply.

considering that no make & model have been provided i will assume it is some low budget untrustworthy model.

 

[MrLitschel]

Have you tested the wall plug to see if it has power? Blown Breaker?