PSP Problems

A of little help here would be appreciated. I have a 3.40 OE-A original black PSP and recently the screen has been turning black frequently (even though the light and the screen is clearly on). I don't think its bricked as sometimes it starts working, though everytime it does start to work it goes back to the set up screen and then eventually switches off again. Also if i put in a UMD and it starts loading the screen just fades out and the prblem starts again. Anyone know whats wrong?