Desktop Start Issue, stuck on CPU post, fans & rgbs working

While browsing on my desktop, my pc just shut down on its own and got stuck at the CPU post light while the Ram RGB & Case fans are running at full speed.

After trying some online solutions, I just completely dismantled the pc and re-assembled it. CPU reseated, ram reinstalled, cleared COMS, etc

The pc started but then rebooted on its on it own a few times. I shut it down and rebooted for the same to repeat itself, eventually I was back to my original issue .ie. stuck at CPU post light with fans & RGB working.

I disconnected and reconnected everything (except CPU). But still not working

Any help please.

Spec.
Amd Ryzen 5 2600x
Msi b450 gaming pro carbon ac
Adata sx8200 pro 256 gb
Gskillz tridentz 3000mhz 2x 8gb
Zotac 1070ti amp edition
Seagate barracuda 1tb

vaibhavyagnik said:

Fans running at full speed, Computer not booting, Computer starting without pressing the power button - All these generally point to a faulty motherboard. Does this board have a backup bios? If yes, you can try manually switching to backup bios.

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I don't think so

nRiTeCh said:

You havent mentioned what power supply you using.
Try with single ram at a time and also enter bios and load defaults.

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Corsair Cx650
I tried with single sticks for ram, but didn't work.
I'm not even reaching the Bios screen