Humming noise and now the projector does not work

To get the humming noise to stop when listening to your iPod while it's docked, you have to use the projector feature AND keep the backlight on on your iPod. My projector stopped working and I'm trying to figure out how to get it going again (replace the bulb?) so I can stop the humming noise again. The unit is not being made anymore, probably because of this problem.