Lately my PC has been crashing (when I do certain things such as just run it on) and I have to push that start button a few times before it actually goes on . Could this be from a PSU dying or just some other problem?
could you be more specific with the types of crashes you are getting? does it simply shut down, is there an error message, is it a blue screen? etc. We need to know what type of problem it is before we can point fingers at hardware.
Make sure it isn't overheating: the PSU or the rest of your computer. Check to see if the PSU fan is running, and check all the connections in the case for loose wires. Hope that helps!
go to start -> run -> eventvwr then hit enter this should run the event viewer and then that will allow you to see all errors for your system even if you do not get a error warning.