Overheating and screen flicker

Two weeks ago my wife's cat knocked my powerbook off our table and it flew into the wall. Luckily it was closed and the hard drive was asleep. I didn't notice anything wrong at first but now my screen flickers whenever I type and sometimes when I open my powerbook the center of the screen is blacked out. So it looks like a letterbox tv (except the middle is black and the background is on the top and bottom. Also my powerbook gets crazy hot just surfing the internet now and I don't hear my fan coming on anymore. Before I could watch a movie and my powerbook got a little warm but now its hot to the touch after 5-10 minutes. I have had this powerbook for 3 years now and there isn't a scratch on it. Should I replace my powerbook or get it repaired? Would it be cost effective to get it repaired or cheaper to replace it? Please let me know what you think!