Pc won't boot

[snipuu]

So my pc was on and i didn't do anything and all of a sudden my pc turns off. it starts but my monitor says no signal and my keyboard won't light up. also other usb things won't work. i have checked that all the cables are on the right places. motherboard's ez debug light is on vga and the light is white. I tried the parts on a different motherboard and the same thing happened but the other motherboad's ez debug stays on cpu. I updated bios and did cmos cleanup. Also gpu fans are spinning for a while and then it stops. the gpu isn't broken because i tested it on my friend's pc and it worked.
CPU: AMD Ryzen 7 3800X
GPU: NVIDIA GeForce GTX 1070
Motherboard: Asus ROG strix B450-F gaming II
2nd Motherboard: Msi MPG gaming carbon wifi B550
PSU: Corsair RM 750X

[Bombastinator]

38 minutes ago, snipuu said:

So my pc was on and i didn't do anything and all of a sudden my pc turns off. it starts but my monitor says no signal and my keyboard won't light up. also other usb things won't work. i have checked that all the cables are on the right places. motherboard's ez debug light is on vga and the light is white. I tried the parts on a different motherboard and the same thing happened but the other motherboad's ez debug stays on cpu. I updated bios and did cmos cleanup. Also gpu fans are spinning for a while and then it stops. the gpu isn't broken because i tested it on my friend's pc and it worked.
CPU: AMD Ryzen 7 3800X
GPU: NVIDIA GeForce GTX 1070
Motherboard: Asus ROG strix B450-F gaming II
2nd Motherboard: Msi MPG gaming carbon wifi B550
PSU: Corsair RM 750X

Seeing stuff like that with ryzen2 machines exclusively all with a time frame of a couple weeks ago.  A generic reason for this would be spontaneous hardware failure, but I’m wondering if it was some sort of update now. Not all changes to computer software are instigated by the user anymore.