Sears garage door opener question
Greetings. I have read many helpful replies to questions about Sears garage door openers here, and IÂm hoping I can receive the same. IÂll list the symptoms and what IÂve done to try and check things out. IÂm guessing that IÂve lost the sensors or the logic board, but please let me know what you think.
Sears model 139.53673SRT1 Â½ hp from 10/97.
It worked fine for 10 years. Starting the other day it will not close the door. It starts, moves a few inches, then stops abruptly and the light flashes, as if there were something in the path between the sensorÂs sender and receiver eyes.
The door moves freely when disconnected. The override (pressing and holding the hard-wired switch) works fine. So, this does not seem to be a mechanical problem.
After using the override to get the door closed, the door will open normally using either the hard-wired switch or the remote.
Changing pressure settings makes no difference.
I can see no glow (green or yellow, although the plastic appears green on both) on either the sender or receiver, making me wonder if power is reaching them. At the motor unit, I read 30 volts being sent to the hardwired switch and just 3 volts being sent to the sensors. I also tried shining a TV remote into the receiver, as was suggested in this forum. No glow in response.
I can place the sender and receiver eye to eye without changing the behavior, so I assume alignment is not the issue.
The remote works fine, in terms of activating the motor. Jumping across the sensor (putting a jumper wire across poles 2 and 3) just defeats the remote. (This, IÂm sure, reveals a noviceÂs mental model; just including it to be comprehensive here.)
I see a blinking yellow light on the rear of the unit (2 blinks then wait; repeat), which I imagine simply means the remote signal is being sought.
We recently had lightning storms, and the door opener problems may have coincided, but IÂm not 100% certain of the timing. I removed and examined the logic board and can see no visual evidence of a strike.
So, is 3 volts normal, implying sensor or wiring problems? Or is this half of what the unit should be putting out, meaning a logic board problem? Or something else that would account for problems exclusive to door closing? Thanks for any advice.