Question Help: PC Sudden Shutdowns

[Overlaust]

Hello, my PC have been having this problem for so long, It suddenly shuts down from time to time without me running huge softwares. There'll be times when it'll open, only to shut down a few mins or hours later. Sometimes it turns back on and say there was a power surge and the motherboard used its anti powersurge function sometimes its just black. There are also times when it'll turn off right off the bat like when the mobo logo shows, or the windows logo shows. Idk what to replace or how to find out what part are actually faulty. I hope you can help me identify the problem. Putting up links on how to identify stuffs if they are faulty like the psu cpu gpu and the mobo will be a huge help, sorry for the long post. Thanks.

Edit:

I5 i forgot which exactly but its a cheap one.
Gtx 750ti
Win 7
8gb ram
Psu used to be a generic brand, replaced it with a true rated korean brand (AON- ATX600WDUAL??) after the problem occured. (didnt know I had to buy a true rated, I think the problem was due to this. Also my father used to plugs it out out of anger hahaha)

 

[COLGeek]

We'll need to know the specs for your system (make/model of all components), version of Windows, anything changed recently, etc to help diagnose the problem.

 

[Overlaust]

We'll need to know the specs for your system (make/model of all components), version of Windows, anything changed recently, etc to help diagnose the problem.

Edited it, also I just opened it right now, it showed like a broken monitor look, i mean like the broken colors and stuff, the monitor is fine, it's on the pc.

 

[Dark Lord of Tech]

That new very poor PSU , won't help the situation.