If the opener's light bulbs do not turn on, but all other functions of the opener seem to work properly, then there is usually a quick and easy solution:
1. Unplug the garage door opener.
2. Remove the light bulb, and check to be sure the bulb is not burned out.
3. Locate the small metal tab at the base of the socket. Clean away any corrosion you may find on the tab as much as possible. With a small instrument, generally pry up on the metal tab to ensure that it will make solid contact with the light bulb.
4. Reinstall the bulb, plug the opener back in, and the bulb should illuminate.