My pc keeps turning on and off

[Loucki]

Hi

My pc of 5 years turns off after a few seconds after turning it on 

A month ago i broke the power botten on my pc so i turned it on with a screw driver touching the power up pins.

It worked fine but after a week the pc turnd off after a few seconds turning it on 

Some time passed by and i replaced the case of my pc the pc worked fine for two weeks and the problem came back 

 

What do i do?

[NetherSand]

It can be many things. My dad had an experience with a psu that caused that problem. It can also be the motherboard or even the power button shorting somehow. Do the screen light up?

[Loucki]

6 hours ago, NetherSand said:

It can be many things. My dad had an experience with a psu that caused that problem. It can also be the motherboard or even the power button shorting somehow. Do the screen light up?

No the whole pc case is new so i dout it but the screen dosent light up only the pc 

Turns on and then it just keeps turning off and on off and on