Sears garage door openers are manufactured by Liftmaster-Chamberlain. These garage door openers are very reliable and will last for years. There may come a time, though, when the opener does not work as it should. By performing some troubleshooting, you will find that most problems are minor and only require small adjustments
No Push-Button Operation Or No Remote Control Operation
Make sure that the circuit breaker has not tripped and shut power off to the unit. Sometimes a surge will occur that will cause the circuit breaker to shut the system off. The remote control may have a dead battery. Unhook the back panel of the remote control and change out the battery.
If you are not able to operate the Sears garage door opener from the wall button, you may have a broken wire or one that is grounding out. Inspect all of the visible bell wire from the wall control to the opener. Make sure that the staples that attach it to the wall have not broken the insulation on the wire. This will cause the wire to short out. Check for loose connection by removing the wall control panel from the wall and inspecting the terminals. Also inspect the wire hookup at the back of the garage door opener.
Door Does Not Shut Completely
When the door does not shut all the way, you just need to make adjustments to the limit switch. Disconnect the door from the motor by pulling down on the emergency release rope. This will disengage the door from the opener carriage. Operate the door manually to make sure that it is not binding anywhere in the travel. If it is, make necessary adjustments and reattach the door to the carriage.
If you found no binding, hook the door back up to the carriage by opening it until it locks into place. Locate the down limit switch on the rear of the motor. Adjust it with a screwdriver by turning it clockwise in small increments. Operate the door by the wall control button and continue adjusting as necessary.
Door Does Not Open Fully
When the garage door does not open fully, you have the same problem as with it not closing fully. Perform the test as before to make sure that the door is not binding anywhere. If the door binds, it will cause the force adjustment safety mechanism to stop the door travel.
If no binding is found, locate the up limit switch on the rear of the motor. This is adjusted with a screwdriver as well. Only move it in small increments and have a helper operate the wall control button. Ideally the door is fully open when the outer edge of the bottom section is at the header height. If it opens any more than that, you risk cable slack, which could cause other problems.