PSU is getting loud

Hey, weeks ago I was the poster asking about help with what was a faulty PSU.  I'm getting similiar problems again, should I return it for a new version of the same type? 

Problem was my computer would shut down instead of restarting like I'd tell it to.  Then it wouldn't turn on for a few minutes & the PSU was hot.
I replaced it with a 500w one, it was real good for a while but now its getting loud and I had a repeat of the same problem, where it would shut down instead of restarting and wouldn't turn back on again for a while.

Should I take it back and exchange it for a new type of the same product or is something else my problem?  There's no leaking or corrosion anywhere, I was told that could a signal of another problem I might really have causing similiar results.

Sounds like you just got a crapper PSU.

One question though, was there a point in time where starting up your computer was starting up an old lawnmower?  Like, you're power on, it'd power up, and it would turn off during boot?

PSU tend to die progressivly like that, not all at once.