CPU/Mobo PC Not booting, blank display, how to diagnose

gourav

Skilled
A few days ago, my PC stopped booting all of a sudden. When I shut it down, it was working fine, next time I switched it on, it wouldn't turn on.

At first, the VGA light on my motherboard was lit, indicating issue with GPU. But after trying a couple of things (removing one stick of RAM, tightening the GPU power cable, etc.), the CPU light started glowing instead. There was a slight change in behaviour as well. When the GPU light was on, pressing the power button turned off the PC. But when the CPU light started glowing, I had to hold the power button to turn it off. There was no display in either scenario.

One kind friend here sent his old GT730 for free to me so that I could check if my GPU was faulty. However, it turns out the PC doesn't turn on even with the GT730. The LED marked CPU glows on the motherboard and nothing happens.

I will probably have to take it to a repair shop now, but before that, is there anything else I can try?

I have the following components
MotherboardMSI B550M Pro VDH Wi-fi
ProcessorRyzen 5600
RAMCurcial Ballixtix 3600 MHz 16x2
GPUInno 3D RTX 3080 10 GB bought recently from Nikhil Singh on this forum
PSUDeepcool PM650D
SSDWD Sn570 512 GB (main) + Crucial P3 1 TB (secondary)
Fans1 Noctua + 2 Arctic PWM fans, 1 corsair and 1 silverstone (came built in) non-PWM fans
 
Remove BIOS battery and unplug power, press power button to drain residual power and wait for 30 secs.
Replug everything and check. Make sure all connections are tight and secure (24 pin and 8 pin CPU power).

Lastly you can remove cooler and reseat the CPU if you're comfortable doing that.