Same thing happened to me. The good news is that it should be an easy fix. Consider one of the folowing from most likely to less so:
1. Using a moistened lens cloth (for eye glasses), swab the disc lens in the player (press open, swab the lens). Don't be afraid to clean well. After all, it doesn't work now so it won't work less if you do it wrong.
2. Make sure your disc is super clean and has no scratches. The older these players get, the more persnickety.
2. Make sure the parental control hasn't been set too low so that no discs will play.
Good luck!
dp0001, December 2009