LCD monitor screw up?

I got a lcd monitor, name and shit are unimportant. buuut. I turn it on, connected and shit, and it flashes the screen for a split second, turns off, and redoes that. i was told its possibly the transformer. any ideas on how to fix it myself? keep in mind Ive smacked it multiple times to try to fix it. no avail!

I'm not kidding when I say "make sure the power plug is plugged in ." It seriously happened to me and freaked me out. Once I wiggled the cord back in place, it worked fine.

Tried it on another computer, or tried another display on that computer?