PSP LCD problems

the left part of the screen (only the left) is flickering, sometimes very dim and sometimes as bright as the others, i would like to ask what is causing this and what your known solutions are, thanks in advance

my guess would be that the backlight is failing, if so then the only option would be to replace the screen

Know any good site which sells cheap ones?

DealExtreme has them from 12-16USD depending on your PSP model. you should also check Ebay for cheaper prices