If your garage door opener suddenly stops working, there are several steps you can take to diagnose and potentially resolve the issue. Start by checking the power source; ensure the opener is plugged in and check your circuit breaker or fuse box for any tripped breakers. If you're using a remote control, examine its batteries and replace them if needed. Test the wall-mounted control switch to see if it's functioning properly. Try manually opening the door using the emergency release cord to verify if the issue is with the opener itself. Make sure the safety sensors near the bottom of the door tracks are aligned, clean, and free from obstructions. If the problem persists, consult the manufacturer's manual for reset instructions. If troubleshooting doesn't work, it's advisable to contact a professional garage door technician who can accurately diagnose the problem and recommend appropriate repairs or replacements.