The sensors in the doorway must be pointed at one another for the light on the receiving sensor to come on. If they are bumped or somehow mis-aligned that light will go out and you will have the problem you describe. Tweak them a bit. You could have a bad sensor but mis-alignment is very common.

Thanks for the reply. Unfortunately, it is the light in the sending unit that wont come on. I even took the sending sensor, still connected to the opener by the wire, over to the receiving unit and get nothing. Must be a bad sensor.
Brad

My reply would have been a little different had you said neither sensor light is on. You need to check the wiring from the opener to both sensors. If either wire is shorted by a staple it can cause this problem. Also check that the wire to the sending unit is not broken or disconnected at the motor.

I have a similar problem - my door suddenly stopped working correctly (Sears 1/2 hp opener, been working great til now). Now door won't close - goes a few inches down, reverses, light flashes. Will close if you hold the wall button until it goes all the way down. Opens normally with any button - remotes or wall. Safety sensor lights do not have the red or green LED glowing on either side - what would make them stop working suddenly? All connections are good - no damage to wiring that I can find. Have no owner's manual (previous owner did not leave it). How can I get an operator/owner manual for it?

One of the sensors is the 'sending unit' and the other is the 'receiving unit'. If the light on the sending unit is not on then the light on the receiving unit will not be on. Your sending unit has quit for some reason. If you are sure the wiring is okay then you either have a bad sending unit or you have had a lightning strike nearby. Lightning usually hurts the logic board which is the brains to the thing. You can get an owners manual from Sears parts if you have the model number off the motor unit.

Thanks - I didn't find this answer, so put another question....have had lots of lightning in the area, so that could be the problem. How can I check the logic board, or do I just need to try replacing it?

There is no way to check the logic board other than replacement. Try calling around to your local shops and see if someone has a used one on hand. The part number is near where all those white wires go. It looks like 41AXXXX

I saw several issues that are similar to my problem. Question? if the sensors are aligned properly, what should the colors be and should both be a continious light or should one be blinking. I too have an issue where the door has always worked properly but suddenly doesn't. If I hold the Primary control button down, the door will go up or dowm until i release the button. I did not experience any lighting strikes in the prior days to the problem. I sure hope someone can help. i contacted a Sears Authorized repair person and he said he would not attempt it. WOW

The color of the lights depend on the model number of the opener. The light should not be blinking and is an indication that the sensors are not properly aligned. Tweak them a bit to stop the blinking. What is it the Sears authorized repair person would not attempt?

My problem is similar....BUT:
The door will go up from the remote. It won't go down but has the typical action as if something is blocking the sensors. So, I noticed when opening the door, that the green LED went OUT about 1/2 way up the door opening sequence. The LED stayed off until the door was 1/2 way DOWN the close cycle - activated from the doorbell button in the garage. I bought a set of replacement sensors but wonder if it's the circuit board now... NO I haven't replaced the sensors yet.

Vorlon,

Have you checked to make sure the sensors are aligned first. You either are going to have a orange light that is on all the time and a green light on the other when they are lined up right. Or you will have one green light that is on all the time and another green light that comes on when they are aligned. Check these if they are not working properly, then replace them. Normally it is just the sensors.

What was the final solutions to problems noted above? I seem to now have same problem(s). Sears garage door opener working fine two days ago and then yesterday it will not close from door bell opener or remote. Will open. Will only close when hold down door bell opener button. Acts as if something is blocking sensors. Have removed sensors from mounting brackets and placed directly in front of each other. Still doesn't work. Neither sensor has its sensor light on even when in front of each other. Have checked and re-checked all wiring and hookups. All check out ok.
Does this mean I must replace sensors?
Thanks.

Sure sounds like bad sensors to me. The light on the sending unit should be on all the time and the light on the receiving unit should only be lit when the two sensors are pointed at one another.

Does anyone know what the correct voltage to the sensors is supposed to be? I have same problem goes up ok, only goes down with primary wired button. One amber on sensor and the other will not light at all. Voltage to each is approx 3.3v but if that is too low then sensor replacement would be silly. 3/4 hp chain drive Sears GDO built 02/05. THX

Measuring the voltage will not help you. There is an infra-red signal that must be detected for the sensors to operate properly. Your receiving sensor is most likely bad. That is a common problem.

Thanks, Don, but it seems if the board is putting out the wrong voltage, then replacing the sensors would be a waste of time and money? The infra-red signal you refer to is generated by one sensor if and only if the correct voltage is applied to the sensor, am I wrong?

Videobill, you are correct it sounds like the sensor voltage is too low. The sensor on most openers I have worked on is between 9V and 24V. The power supply of the opener puts out a DC signal which allows the sensors to power up. The sending unit blinks the LED on and off at a rapid rate. The receiving unit sinks the power line down to a low voltage when the LED in the sender is detected. This happens fast so the power is not depleted from the units. Opener is then able to detect the proper operation of the sensors to create a "fail safe" system.

I seem to be having the same problem. Worked okay in morning but not that night. I've tried adjusting the sensors to no avail. One has a green light all the time and the one with the wire a geen light on and off. Can open from car or house but can only close by holding button in garage down. Any suggestions?
Thanks

I found the problem with my door going dn a few inches then reversing and the light blinking. i oil my door and track like every 6 months. and i know my sensors were good
and dont move.So What i Did was oil the shaft under the sproket that turns the chain.on the top of the opener and on the first try it worked no problems ever since. hopes this helps.

I have Craftsman 1/2HP 139.18850 (1995).

The door or remotes won't open the door and I found another post that seems the same problem. "When pressing the wall button or outside keypad the motor (41A4315-7C) hums twice and does nothing. The green light up on the motor blinks 5 times, stops, blinks 5 times and so on"

Seems to indicate...The LED is blinking the code for "RPM sensor or motor overload".

I bought the 41C4398A RPM sensor assembly part and replaced it and the same problem happens so it's not the sensor itself.

My gears (worm, drive) look fine to me, a little chewed but still look 100% fine to me.

What else could cause the RPM sensor to stop the motor from turning? Is there some way to force turn the mechanism to see if it's jammed on a gear or tooth.

Not sure what to try next.

Andrew

Andrew,

Have you found a fix yet? I have nearly identical issues as you. Crafstman 1/2 HP (Aug '95). My only difference is that the Green LED blinks four times repeatedly. Do you have the code for this?

Matt

Please Help me,

I just replaced my old Craftsman GDO with a new Craftsman unit, The installation was pretty easy. The problem that I am having is with the car remotes, I programed them at the motor just as the instructions said, to test them I got off the ladder and walked out to the driveway, about where I would be when I used it and no luck??
I kept trying it until it worked but I was inside of the garage?? Walking backward and trying it again I am now about two feet from the garage door and it works...with the door open once closed, it does not work at all

The old unit opened as we came up the driveway no problem!

Any thoughts??
Happy New Year
Fred

I have a 10 year old Sears garage door opener that just quit.
There is power to the unit, however the two lights do not work and pushing the light and lock buttons on the console will show zero effects.
The garage door will not open or close.
There is no moice coming from the opener.
I checked for GFI trips and did not find any.
Need help!!!

Door will open but will not close with the remote button but will close if I hold the wall unit button down. If I hit the wall unit button once, the door opener lights starts to blink and the door does not move. One sensor lights is constant green and the other is constant amber. If this normal or are they both to be green? If I jiggle the sensor, the door will close once and once only. After that, it is back to holding the wall unit till the door is closed. Any ideas?
Thanks in advance.............Irish

If jiggling the sensor causes it to run once then I suspect bad wiring or maybe the sensors are loose and moving when the door runs. The lights are the correct color for your model.

I've been reading quite a few posts regarding issues with the Craftsman openers and wondering to myself, was it a smart way to go? I guess hind sight is 20/20. So, Christmas '07 we purchased a Craftsman 1/2 HP garage door opener as a gift for my mother-in-law. Less than 1.5 years later we're experiencing the same symptoms as schneider-rolfo. Door will not open or close or make any noise whatsoever when using either the remote or the hardwired console. The remote stopped working a few months ago and replacing batteries didn't resolve. Now, neither console or remote do anything. I noticed that one of the sensors' LEDs will not light regardless of alignment while the other is working (I don't recall if it's green or amber, but know that it is lit.) Could the issue be caused by a faulty sensor or might it be something else more serious?

Sears, who did the install, wants $65 just to come out to diagnose the problem and I'm sure it will be more to have them fix any issues as the warranty on these I've been told are only 60 or 90 days. Any thoughts before I spend the cost of a new opener to get someone out to look at and repair it?

Thanks.

I bought the garage door opener from Sears a 1.5 years
ago.It works fine. On Monday i use the button wall control
to open the door. The door go up haft the way and stop and no power to the motor, it's completely dead and i wait for
about 3 minutes and the power on and the door moved up about 1 foot and the power off again. It keep doing that on and off but the door open haft no up or down. I'd like to know What's wrong to it? It can fix or i have to buy a new one? Would some body have any idea? THank you.

my wire broke right at my sensor housing, how do I get the wire connector out so i can rewire the connection.

Here's what i did. the sensors are a PAIN in the you know what.... The morning sun would also interfere with the infrared signal and i'd have to stand in front of it to block the sun lol, someone was always kicking them out of alignmnet or a ball would hit it, or you have to bag them to keep them from getting wet......ANYWAY....I removed the sensors from the bottom of the door, taped them together so they are looking at each other, and put it up out of the way...NO MORE SENSOR PROBLEMS SINCE!!!!!

The belt came off my sears craftsman garage door opener. How can I get it back on?

my garage door opener suddenly stopped working. the opener will not open from either remote or wired switch. the green light is blinking slowly on and off. i hear a click for a few seconds when it is actuated but wont move. the gears are good and door moves freely.

part # 41a4315-7c

I have a 1991 Sears 1/2hp Model#139.53615SR
Within the last month or so The door will open up on it's about once a week I come out and find the garage door is open. I've made adjustments on the force control. Please advise much appreciated

I have a lift-Master model #1000SD. Garage door will only close if i press AND hold button down on either wall mounted button or remote. If i just quickly press button it will begin to lower but will suddenly back up and light bulb at the unit will flash about 5 times. The light indicator on either sensor is no longer lit at all. I inspected wiring and all connections as best i could and saw no loose/shorted/crimped wiring or anything to cause it to go out. Their is also a green LED flashing 2 times every 5 seconds or so at control center of unit.
note:The Lift-Master garage door WILL raise as it should without any problems at all, the problem is with it lowering. This problem began to occur after a lightning storm just over my area.

please advise