How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask AssuredElectrical Your Own Question
Category: Small Engine
Satisfied Customers: 4241
Type Your Small Engine Question Here...
AssuredElectrical is online now
A new question is answered every 9 seconds

Garage door opener Model 139.18515SR - 1/2 hp My door will

Customer Question

Garage door opener Model 139.18515SR - 1/2 hp
My door will only move 5-10" up or down.
Manually it works fine
When I disconnected wires, I found the 2 that control. Even sparking them together door only moves 5-10"
how can I fix this?
Submitted: 1 year ago.
Category: Small Engine
Expert:  AssuredElectrical replied 1 year ago.

Welcome. My name is ***** ***** would be glad to assist.

Please provide some more detail on the situation.

1. By manually, you mean you disconnect the door from the trolley and move it by hand, correct??

2. How do you get it closed to see if it only moves 5-10"?

If it is open and only moves 5-10", how does one verify that when closed it only works the same amount?

3. Are you trying to set a keypad to operate 2 doors? Or is this a hand held remote for 2 doors?

4. Does the wall control operate the door properly?

Let me know and we can continue


Customer: replied 1 year ago.
1. Yes
2. It was in the closed position to start. When I push wall control or car it only goes up 5-10" even if I continue to hold down button on control, when I stop and press again it goes back down
3. No I have 2 separate openers with individual controls and remotes.
4. No it and the car remotes have the same results
Expert:  AssuredElectrical replied 1 year ago.

Ok, thanks.

Based on the information, it appears the RPM sensor is no longer operating.

It mounts on the rear of the motor and watches for rotation.

When the motor runs and the door moves, the sensor normally allows to continue, but in yours, it is stopping the operation because it does not sense the motor movement.

It is a small board on the rear, if you open the covers and inspect the drive assembly.

Maybe it is just loose or the wires became disconnected.

Otherwise a new sensor is necessary.

Customer: replied 1 year ago.
I will take a look. Thanks
Expert:  AssuredElectrical replied 1 year ago.

Very good, keep me posted and we can continue as necessary