broken joystick????

My left joystick is broken, when I play any game for example an FPS, my screen with always look up... it feels like something is broken in it.. Were can i get it fixed??? sony? local store? any help?

Thank you.

Chris

Here these two links might help you

http://www.psp411.com/show/guide/53/0/Changing_PSP_face_plate.html

http://forums.maxconsole.net/archive/index.php/f-131.html