Help: Unknown PC Component has died

[Oblaci]

I've recently transfered my old pc contents in to a new case,

 

Every since then the PC keeps restarting until I get to dual boot, selecting either OS keeps restarting it as well (I've tried swapping a new HDD so I know the old one isn't at fault, whit the new one when I tried to install a fresh copy of Windows it restarts mid way). I've narrowed it down to two possible culprits, either the CPU and the PSU? I don't have an extra one of either to swap and test to see which one is wrong.

 

What do you think I should do? Does it sound like a similar problem you've had?