When the light bulb is not working?

When the light bulb is not working, especially on a garage door opener or household fixture, you should go through a systematic troubleshooting checklist to isolate the cause. First, assume the bulb itself has failed, as this is the most common reason. Incandescent bulbs burn out from filament breakage, and this is accelerated by vibration in garage door openers. Replace it with a new bulb you have tested elsewhere. Second, check that power is reaching the socket. Make sure the wall switch is on, the circuit breaker has not tripped, and any GFCI outlet upstream is not tripped. For a garage door opener, verify the opener is plugged in and the door still operates, which confirms AC power. Third, inspect the socket. With power off, look for corrosion, black burn marks, or a flattened brass tab at the bottom that no longer contacts the bulb. Gently lift that tab with a small screwdriver. Fourth, consider the control. Many garage door openers have a light button on the wall console that can turn the light off manually, or a motion sensor setting that disables automatic lighting. Press the light button to toggle it. Finally, if a new bulb still does not work after a power reset where you unplug the opener for 60 seconds, the logic board's light relay or the socket wiring harness has likely failed and needs replacement.