Hey all,
So a few days ago my computer started shutting off when jarred, as in set a book on it... close the cd rom drive door thingy a bit to roughly (it's very sensitive, I'm not like kicking it or anything). At first I would be able to turn off the psu for a few secs, flick it back on and it would be fine. Now it's getting even more finicky and at times will just turn the cpu fan on for a sec and then shut off. I've checked all connections... is this a simple case of the psu failing or is something else shorted? The psu was brand new 3 months ago... so it should still be under warranty. How do you guys think I should proceed?

if its still under warranty, just replace it.

also, you might want to check to see if your power cord may be slipping out of the back (but you already probally did so...)

Yup, get it replaced. The problem might go away and then come back after the warranty times out.

"The psu was brand new 3 months ago..."

What's the make/model/wattage of the PSU? If you didn't pay at least $50, it's most likely garbage.