Question PC wont start immediately after shutdown

[Baboo_345]

So guys I'm having a weird problem with my PC. My pc would work properly that is unless I shut it down. It would then just turn on for a brief second all fans spin up and then it's dead. Pressing the power button wont do anything unless I unplug the socket from the wall and wait for the motherboard light to go out. It will still then turn on for a brief second and then turn off. The only way to get it working is to leave it for 2 hours and then will work properly without a hitch. I even left it for 12 hrs and it was still working in the morning. I tried removing the gpu, hdd, ram sticks and it still didn't work. My psu is just one month old and still under warranty. Any suggestions on what to do?
My specs
I5 3570
8gb ram
Asus p8h61 mobo
Gtx 1060
Thermaltake litepower 450w ( I know it's bad but in my country it' the only one avaliable)

 

[Grobe]

It is probably te PSU that is not good anymore.

 

[Baboo_345]

It is probably te PSU that is not good anymore.

Should I rma it? I just want to be sure before doing it

 

[Grobe]

Maybe. You can't be completely sure just like that, but I'll say it is higher probability for the PSU being the cause than other components.

It cannot be ruled out that the motherboard is faulty as well.