Pc problems after power outage

hi well i have a problem, 3 days ago i was playing skyrim on the pc when the light went off, i was about to go to work so i didn't try to turn the pc on again, and i just left to work later when i came back i tried to turn the pc on and it wasn't turning on i pressed the power button like 20 times then i opened the case, and tried to jump the power pins on the mobo, but nothing happened so i thought the pc had fried or something, then i realized that the mobo has a small led light which indicates if the mobo is receiving power and it was on so then i disconnected the main power cable of the mobo (is the large cable that goes from the psu to the mobo) then i reconnected it again and the pc turned on, it was ok so i went to check my email and it was working good until i started playing skyrim again after 2 minutes playing the pc turned off and on again, i thought it was skyrim so i tried other games and the same thing happened again so i don't know if its the psu or it can be something else i already ordered a new psu and a power surge protector, what do you guys think?

oh also the pc does not turn on easily, i have to press the power button like 20 times for the pc to turn on

the video card fans are working so that's not the problem
the cpu has an aftermarket cooler and it is NOT overclocked, the fans are also working fine

any help would be greatly appreciated .