black screen

I have an Inspiron 1501, recently the screen began to flicker and go black.  It has now become black and won't recover. By black I mean it appears black, however you can still see it with a flashlight held close. I ran the diagnostics and received one code: 2000-0333  "graphics test timed out waiting for keyboard response". I am using an external monitor and it works fine that way.  Any idea what the problem might be?