


If you open the case: It's always worth it to visually inspect any capacitors to see if they're bulging at the top: they could keep the laser from working even if everything else seems to be OK. Confirm that the (tiny!) plastic lens is indeed still on the laser assembly: we've seen one optical drive where the lens popped loose and was rattling around in the case: gluing it back fixed the optical drive.(You should also hear noise as the laser assembly moves back and forth trying to find the beginning of the disc.)

If not, it's possible that the ribbon cable to the laser assembly came loose or needs to be reseated.
