My desktop is windows 7 and it keeps shutting off unexpectedly usually about 15-25 minutes after I turn it on. There are no error messages or anything of the sort, and it isn't overheating. The computer is my first build and is like 7 years old. After some googling it looks like my PSU is dead. Does that sound right? Should I take this as a sign and build a new gaymen pc or is it not hardware related and could be easily fixable?

Pic unrelated but cool