The opener is a model 139.5398511. Without the door attached in the up position, the trolley travels 12" then reverses.

Jimmy K EXPERT February 06, 2009

If the garage door will close when you hold the wall control button in, and the remotes only make the door go down a few inches and return, the problem is in the door safety sensor circuit.

Look at the led's on the door sensors. If one or both leds is blinking, the sensors are misaligned.

If one of the leds is not on, the door sensors need to be replaced.

If the led's on both sensors are off the problem is in the logic board or the sensor wiring. You need to look closely at the wiring to the sensors to see if it is broken or pinched by a staple. You can test the wires with an ohm meter for continuity or two wires shorted together.

If the wires seem ok, remove the sensor wires removed from the terminals on the logic board and check for voltage across terminals 2 and 3 on the logic board. You should have 4-5 volts dc. If you don't have 4-5 volts between terminals 2 and 3 and the opener is plugged in, the logic board is bad.

If you have 4-5 volts at terminals 2 and 3, and the wiring is ok, replace the door sensors.

While you have the door disconnected from the trolley open and close it several times and check for binding. Open the door half way and let it go. It should stay where you left it. If the door opens or closes when you let it go, the door springs need to be adjusted.