PC won't turn on after power light on with no other activity

[ChootsMagoots]

Last night I walked into my room and saw that the power light on the desktop I built was on with no fans, screen wouldn't wake up, no other activity. I tried a single press of the power button, with no noticeable result, then I held down the button to turn the light off (successful) and went to sleep. This morning the computer won't turn on.

I tried turning the PSU off and on before cracking it open and unplugging and replugging all sorts of things with various attempts at posting/booting along the way (posting is a term I only inferred the meaning of from a few forum posts I looked at along the way). I tried unplugging all drives, all non-essential power to other components, BIOS wires, the graphics card, and anything else I noticed along the way.

I also got a security notification from Microsoft that someone may have accessed or tried to access my account. Maybe there's an attack that ends with bricking the machine?

Does anyone have any input?

Many thanks.

 

[hang-the-9]

Need full system specs including the power supply brand and model.

Could be a dead power supply or motherboard as the two most likely things. Most other issues would cause the computer to power on but not work properly. You tried another power outlet or cable or not? If not, do that and see if it works.