Question Monitor no signal, mouse & keyboard shows little sign of life.

[Fejiin]

Ryzen 5 2600
RX 590 8gb
NZXT Kraken x62
Corsair Vengeance 16GB RGB 3000 mz
B450-F gaming motherboard.
650w Bronze PSU

Finished building yesterday, worked fine then.
Today I was playing games and all of a sudden my screen went black and my keyboard and mouse died. But my pc was still running. I waited 5 minutes and the just turned off the power.
My pc still turns on but Monitor/mouse/keyboard dont work. But they work on my laptop.
My RGB lighting and fans are still working.
I've tried restarting the rams, Refitting the GPU. I even put it in the 2and slot just to see what that'll do but nothing is happening.
I feel like either my motherboard is at fault. My power supply is too low, or my GPU got fired idk. Help please.

 

[Ralston18]

Any beeps when the pc fails to boot? Any LEDs. Refer to the B450's User Guide for meanings.

Make and model 650 Watt PSU? Age, condition?

If you have a multimeter and know how to use it or know someone who does you can do some testing on the PSU:

https://www.lifewire.com/how-to-manually-test-a-power-supply-with-a-multimeter-2626158