Computer turns on, then off then boots normally

[whitestar_999]

PSU won't be damaged from this,in fact if your last two psu were damaged then it may even indicate some issue with your room wiring/socket.If possible take your entire cabinet to some friend/neighbour house & check there.

 

[dexterz]

Were you able to fix the issue? let us know how its going.

 

[ranjan2001]

I had exactly the same problem, did almost everything you did but finally found that the BIOS chip (Hardware) had the problem, took the computer for local motherboard repair as it was out of warranty. They flashed the latest BIOS but that didn't help then they did a bios chip level resetting that also didn't work, then they found the circuit to bios chip was faulty which they repaired. Now I don't have this problem. BTW my computer is 11 yrs old.