How to repair my PSP?

I accidentaly dropped my psp in a bucket half filled with water. After I dropped it i took it out and a split-second. After I took it out, I gave it quite a few jerks to make sure that water comes out completely. I put it in the charger to see if it can be charged, but the orange light just blinked for a few seconds and just stopped. So I left it as it was. After 2 and a half monjths I plugged it in the charger and it just started to work just fine. I played a song in it and after some seconds the screen blacked out( after blinking for a moment). I tried to switch it off and start again but everything(as far as I know because I haven't checked the gaming features or the UMD reader) is working fine except the screen. It is still blacked out. Please Help. Don't wanna lose my PSP...... Thanks....