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Chamberlain Garage Door Opener
Posted: Tue Jun 10, 2014 8:53 pm
by dusty
JPG40504 wrote:Let me rephrase the question. Are there any limit switches. I get the impression no. Again timed travel Boo Hiss unless revolutions are counted and drive has no slack/slipping!
There are no mechanical switches associated with the door or the track. There could, I suppose, be limiting devices within the electronic circuitry but the documentation does not speak of them and I see no evidence that they exist.
There does not appear to be any relays or latches either. Relays such as those Ed in Tampa discusses.
Posted: Tue Jun 10, 2014 10:14 pm
by JPG
dusty wrote:There are no mechanical switches associated with the door or the track. There could, I suppose, be limiting devices within the electronic circuitry but the documentation does not speak of them and I see no evidence that they exist.
There does not appear to be any relays or latches either. Relays such as those Ed in Tampa discusses.
Ain't micro computers wonderful!:D
Posted: Tue Jun 10, 2014 10:32 pm
by Ed in Tampa
On my opener the limiting switch is tunable. I can let it stop and then move the pot on the switch just a little and door moves further shut. I have my down position set so the spring on the arm that attaches to the door is slightly compressed. THat means it is pressing down on the door with as much force as the spring has.
My door opener is a old model and it uses small tiny relays solder to the circuit board. I would guess they would still do it that way but I guess they could do the same thing with transistors. Probably have an all solid state latch circuit. However I would still think they would use at least one relay for motor power circuit.
The obstruction sensors the infared light and sensor could be the problem if the sensor got weak and wasn't detecting the light. But I don't think circuit would allow the door to go down by holding the button on the master.
My opener does had a load circuit if the load gets to high either lifting or going down like something stopping the door it will kick in but again the button on the master will not over ride it.
All this talk about openers got me looking at mine. I was running really well about 3 months ago but now it seems to have a funny sound. Got up and looked in and some bird had built a nest inside it. I usually open my door in the morning and unless we leave the house we leave the door open until evening. So doing the day the bird must have figured this would be a good place for a nest. I pulled tiny twigs out of the thing until I had a huge hand full and then I got the shop vac and cleaned up the rest.
Put up a not for rent sign to give the bird a hint.

Chamberlain Garage Door Opener
Posted: Wed Jun 11, 2014 7:34 am
by dusty
The sun has not yet risen but today is garbage collection day. I put the containers by the curb.
Yes, the garage door opened and closed, in the dark of night, using both of the remotes and the master.
So what?
The wires are good. The sensors are functional. The logic board works. The motor and motor control work. The remotes are functional. The master control works. The Lock Feature is turned off. There is no blinking led.
In other words - All Is Well. Well, at least for now.

Posted: Wed Jun 11, 2014 9:29 am
by Ed in Tampa
Sounds like a job for the Shadow. "Who knows what evil lurks in the heart of the garage door opener? The Shadow does!":D
It is sounding more and more like the obstruction sensor problem.
Could they be getting too hot and having a circuit open up?
Me thinks you will have to wait until a failure and read the code in the blinking lights.
I hate it when intermittent problems happen. Seems like things work fine when you have time to fix them but let yourself get the least bit rushed and they strike. Frustrating. Let us know what it is Dusty and best to you on this one.
Posted: Wed Jun 11, 2014 9:53 am
by dusty
Ed in Tampa wrote:Sounds like a job for the Shadow. "Who knows what evil lurks in the heart of the garage door opener? The Shadow does!":D
It is sounding more and more like the obstruction sensor problem.
Could they be getting too hot and having a circuit open up?
Me thinks you will have to wait until a failure and read the code in the blinking lights.
I hate it when intermittent problems happen. Seems like things work fine when you have time to fix them but let yourself get the least bit rushed and they strike. Frustrating. Let us know what it is Dusty and best to you on this one.
That will happen today when we have to leave the house at 12:30pm for an early afternoon doctor's appointment.
BTW: Sun is up and the opener still works under remote control.
Posted: Wed Jun 11, 2014 11:02 am
by JPG
Have ya figgered out a way to eliminate the step ladder trip? Mirror? Light tube?:)
Posted: Wed Jun 11, 2014 11:31 am
by dusty
JPG40504 wrote:Have ya figgered out a way to eliminate the step ladder trip? Mirror? Light tube?:)
Yes, I can now see the led from the garage floor. I removed a shroud that was around the master unit.
I tested the door at 8:00am. The remote works to open the door but the door will not close under remote control. The door will close by pushing and holding the master door control.
I am now convinced that this entire issue has something to do with the strength of the invisible when exposed to the sunlight.
PS The led blinks four (4).
Posted: Wed Jun 11, 2014 11:39 am
by JPG
dusty wrote:Yes, I can now see the led from the garage floor. I removed a shroud that was around the master unit.
I tested the door at 8:00am. The remote works to open the door but the door will not close under remote control. The door will close by pushing and holding the master door control.
I am now convinced that this entire issue has something to do with the strength of the invisible when exposed to the sunlight.
Tube around the 'detector' to shield it from sunlight?
Posted: Wed Jun 11, 2014 11:50 am
by beeg
Dusty, did you see this from JPG'S link?
"The Lock Button on the Door Control
The lock button on the door control may be activated. Press the button to turn this feature off. The light bulb will blink two times. This feature is designed to prompt you that the lock button is activated. When the lock button is ON the garage door opener will work from the door control but the remote controls are locked out."