Psp won't turn on unless i bang it on hard surface

[brother.gigawiz]

I Don't Think it's software as i have had 5.00 m33-6 and it was fine for awhile then this started happening so i updated to 5.50 GEN-B and the same thing happened and i went all the way back to 3.80 and it still did it so i decided it wasn't software and went back to 5.50 GEN-B... but i will try the compressed air and if that doesnt work... i just got myself a $200 doorstop.....

*edit*
lol... i just saw the typo edit....
well, now at least you know my fw history... ill see what i can find....

----Added 28/9/2009 at 9:05 PM----
Fixed! I guess when it dropped the cable that connects the main powerboard to the lcd had become slightly disconnected. i went to take the board out and the cable came out so easy i thought i broke it...... but now it is all fixed. no problems..... no freezing anymore.... ty all for your help... it was greatly appreciated.