Power cable on computer

[yaki]

Could it be a PSU problem?

Nah. Not unless the power supply is already so hot that it's been on fire for a few days. The fact that it's getting that hot means that it's dissipating substantial power, which means that it has significant resistance per unit length, which a cable should not if it's intact.

You have had a fair amount of issues with this computer you just bought. You need to pray to the tech gods that nothing else happens.

Once things start catching on fire, it's too late for pretty much everything other than the mass ritual sacrifice of babies.