please help me to fix my PSP slim....

I have a problem with my PSP.
I thought it was the joypad so I bought a new one but it did the same thing even with the new one.
I now removed the joypad and still does it,have a look at my video here http://www.youtube.com/watch?v=eE0QHLFl1YU
It seems the cursor is moving up or down on his own madly if I go into the web browser the arrow it is steady up in he left corner,please help my son......
Thanks a lot.

clean the contacts with rubbing alcohol

Which contacts the one on the mainboard ?
The joypad is not inserted at the momkent.

thanks

Yes, on the mainboard.

I cleaned it still not working,what could be?
thanks

I advice you to clean with alcohol..