FREMONT — There are numerous ways for a garage door to malfunction, and each exhibits a different symptom. Depending on the nature of the symptom you’re experiencing, it may be worthwhile to do some troubleshooting before calling a professional.

If your garage door is stuck in the closed position, it may be due to a problem with the emergency release. By disconnecting it from the motor, the emergency release allows you to open your door manually in the event of a power outage or motor malfunction. After pulling the emergency release (the red rope hanging from the motor rail), attempt to open your door manually. If you can’t open it, the problem is most likely a broken torsion spring, which does most of the heavy lifting when the door is opened.

On the other hand, if your garage door is stuck in the open position, don’t pull the emergency release—depending on the source of the problem, this may cause the door to fall down or go off its track. Often, a garage door’s inability to close stems from an issue with the safety sensors, which prevent injury and damage by arresting the door’s movement when something is in its way. Check for obstructions that may be blocking transmission between the two sensors, which are located at ankle height on either side of the door. You can also try readjusting them, as their “eyes” may be out of alignment with one another. If you still can’t get the door to close, call a professional.