Trying to get homebrew running on your PSP? Want to add a screen light to your Game Boy? Trying to figure out how to work your GP2X? By popular demand, discuss it in here! (This forum is for pre-built handhelds, NOT custom made portables!)
What is the picture showing? Is the screen just all black? Can you see anything at all, or are all the pixels the same?
Try adjusting the contrast dial. It might have gotten turned all the way up. If that doesn't help, you could try opening it and looking at the screen's ribbon cable to make sure everything is connected right.
If the screen doesn't change when you adjust the contrast, and you are sure that there are no problems with the ribbon cable, or how it is connected on both ends, there may be a problem with the circuitry that is connected to the screen (sending bad data), or the screen could be broken.
You might want to PM Bibin or palmertech if you want an expert's opinion.