Computer won't turn back on!

[Poith]

I just built my computer 3 weeks ago. Was running fine for 3 weeks & I was playing H1Z1 today and my computer turned off. It wouldn't turn back on. If it's the power supply, can I try using a different one from a different computer?

 

[CountMike]

Could be practically anything but try another PSU first, just make sure it's within specs for that computer.