If your LiftMaster garage door is stuck and won't open, it is possible to troubleshoot it in a variety of ways. Doors can get stuck due to problems with their power source, photo eyes and track alignment, among other things. Fortunately, resolving many of these problems can be done safely by the layperson and doesn't require specialized tools.
Before You Begin
Before you start troubleshooting the door, you should do a preliminary check for broken springs. When the tension spring on a garage door snaps, it usually makes a great deal of noise. In addition, it may spring across the garage due to the high tension. Look for a spring that is missing, broken or hanging from just one hook. If the spring has broken, you should contact a professional for assistance.
You should also check to be sure that the door isn't binding. This can occur when the door's trim board is installed too closely to the door itself. You will typically notice signs of this problem when the door is closed. One way to resolve this issue is to shave off the excess wood until the trim board is flush with the door's framing lumber. If this is not effective, you may need to contact a garage door repair expert.
Power Source Problems
If your door isn't binding and its springs are in good working order, you may be able to make easy repairs yourself. The first thing to check in this instance is the power source. The opener needs to be plugged into a working outlet. Be sure the cord isn't damaged or disconnected. In addition, check to be sure that the circuit breaker to your power source is still open.
Photo Eye Problems
Most garage doors rely on photo eyes placed on either side of the door to determine whether there is something blocking the door. If the eye senses a person or object in its path, it will stop. This is an important safety measure. However, it can be problematic when the photo eye does not properly see the opposite sensor, as this will make the door stop due to a perceived object in the way.
To resolve this issue, check to see if the cord to either photo eye is cut or damaged. In addition, clean the surface of the eye. Dust and dirt that collects over time can cause similar difficulties. The eyes must be perfectly aligned with one another, so use a laser level to ensure they are properly lined up.
It's possible for the track on which your garage door slides to become bent, dented or warped with time. If the track has suffered any of these types of damage, you will need to fix the track. With the opener unplugged, use a hammer or rubber mallet to gently hit the track back into shape. If it isn't possible to do this, you may need to consult a professional.