so do I just use my multimeter (total noob with multimeters, bought one today) and place a black and red lead on the two screws of the back of a sensor to see if it reads 11 (or similar voltage) while in the DC mode? I suspect my logic board is out since I installed new sensors and no lights are on either side - I don't think my wires are damaged since they are in the ceiling and walls but you never know. If this is a logic board issue I'm going to just buy a new unit since it's half the cost of a new unit

Hi, new Genie has 13 volts at motor but zero at sensors and wired wall switch. Door does operate up an down with limit switches. Motor clicks when remote is pressed but nothing happens. Retraced wires 10x's and do not see any irregularity. Sensor swich connectors shox audible meter continuity. Sounds like a bad wire? BTW the Genie door is of very poor quality. Would never buy again. Threw away box so probably can't return. Call Genie and a lady with an algorithm chart reads it off. What would you do?

Exactly what I was looking for, thank you.

My green sensor comes on intermittently. Power is fine, alignment is fine. Door works fine if green light is on. However, the green light randomly goes out and door wont close. Any ideas?

Thanks for posting! This is the video that helped me diagnose the issue: Bad sensor. Popped in a new set and we're up and running! The wiring diagram was clutch. Much appreciated!

What if neither the red light nor the green lights are on but I have power to the opener head?

my sensors light up and appear to work properly, but the door wont go down, and unit flashes 10 times. Chamberlain tech support said could still be a wiring problem, not bad sensors. The sensors could be getting power enough to light the leds, but a bad wire connection can screw things up. The way to check bad wiring is called the short wire sensor test.

Silly question, but isn’t the unit plugged into an outlet, so shouldn’t the voltage be in AC? Or is the unit converting the incoming AC voltage to DC voltage for the output to the sensors?

Everyone else deals with blinking. Thanks for video on no light.

Did you check the voltage across the green sensor when running the garage door up? My voltage drops down to 7V and the green light flickers and sometimes will stop the door.

Awesome explanation, I had no light on either sensor. I thought the sensors were bad. After doing the test you suggested I was able to diagnose the wiring was bad. Thank you.

One of the best summaries on diagnosing the sensors. Simple and understanding.

Whats the nearest road this off of?

Thank You !!!

My green side is getting like half the voltage when I connect the wires. My voltage is reads ~12v at the wires themselves then like ~6v when I connect and measure at the prongs. I've already replaced both sensors with new. Thoughts?

Upgrade your sensors to Infinity Shield sensor. Those photo eye have so many issues!

Your simple wiring diagram was the key to enabling me to understand, diagnose, and repair a wiring problem, which was essentially disconnected sensor wires in a jumble. That diagram was flashed quickly at the beginning of the video, so I had to take a screenshot to have time to adequately digest it. Your simple diagram was far better than more complicated ones in other installation and troubleshooting instructions. As complicated as it needs to be, but as simple as it can be. Well done!

He clearly did cut you off trying to get back on the interstate.

Thank you for this video. I can diagnose that my sensor is bad since the voltage is present.

Oasis from TMNT

Im having a problem with the sensors i got a new garage door opener and sensors 3 years ago and last week the sensors keep turning off, i unplug the garage door motor and plug it back and the sensors stay on for 1hour and die, what can this problem be? Thanks for your helpfull video

Neither garage door sensor lights up, bought a new control board installed it same problem. So I did a sensor bypass with 1 ft of wire and it worked, so then I replaced both wires and am having the same issue please help

Dumb dudes ruin this world.

This was extremely helpul!!

I have a Lunear garage door opener. One has a green and red light the other just a green. It will not close with controls but will with the big one on garage wall. What to do?

Depends on what you paid.

Great noise. I love it. That is one clean drain.

Sorry, you are missing a major point how garage sensor set works. I also though it was voltage or no voltage thing, but there is lot more to it! Sensor (sender) sends the infrared beam via pulsed square wave and the receiver sensor constantly receives the pulsed beam (square wave) when there are no obstacles in between. When beam is broken then there is only one state on receiver (on or off zero or one) This depends on model of sensor set, but bottom line, *with beam broken there is no change of state that is normally every few milliseconds.* This is quite clever, if the sensor set fails in either in on or off (zero or one) state (signal or no signal) then garage opener electronics will consider that sensors are malfunctioning and this will prevent garage door to close. This is why you cannot bypass the sensors, it is by design. I have also learned this the hard way after I bought new sensor set and only after I connected my oscilloscope to it, just like this gentleman is demonstrating here: kzbin.info/www/bejne/fZPQppmOnNWfZ5Y

How frequently is it a bad sensor vs. the wiring? My sensors are 20 years old.

Thank you so much for the video my sensor harness turn out to be 2.7 volts but the red one did not light up so I went to lowes bought new ones and now we’re back on business Genie sensors

I had find out the both green and orange sensor have no light but if i took green sensor wire out from the power supply in garage opener then other orange light sensor is on. Im really confusing why it doesnt work. Can you please advise ?

If you are getting less then 11 V at the unit, is the unit bad?

Very good video explaining the possible low voltage issues one may have with garage door sensors. Thanks!

Im falling asleep....

My issue is that both sensors are lit up and one light will turn off if my hand is in front of it, but the door just acts as though its being blocked and auto-reverses no matter what I try .

Can you install more than one sensor pair, say one pair at 6" from the floor and another pair at 36" from the floor?

Hey Todd, may I have your permission to feature this clip in one of our compilations on our main channel "Car Crashes Time"? You'll be credited when the clip is used of course!

Hi, is it ok if I feature it? Credited on screen and with a link back! Also, is there any update? And is there any more footage?

Hey, may I feature this video? With credit and with a link back to you! any update? where did this happen? What happened before the video started??

Thanks for the information and video. There may be resistors in series with the power/signal terminal on the inside of the motor unit, so 11 volts may vary. The resistors would also provide some protection to the motor unit if the wires accidentally get shorted together. I've seen an article that measured 6 volts with the sensors connected: pages.mtu.edu/~suits/electronics/GarageElecEye.html Using only two terminals on the motor unit, one being ground, then the other supplies power and receives the signal, so there is some manipulation of the sensor power line, at least for the Chamberlain style transmit/receive sensor pair. Still looking for schematics of the insides of the transmit/receive pair. Because I've got nothing better to do than repair a $45 part?

Thank you so much you saved me hundred of dollars in repair!

I have a Chamberlain and the voltage for the door sensors are 6V DC "The output voltage for the door sensors should be between 5-6 volts DC "

Ahhh the reason our quarry got shut down, the students

Why did you test in DC voltage? Isn't a garage door opener AC? Just asking.

thank you for the explaination. I have a genie powermax 1500 and the sensors are pointed appropriately, and lights on both units are on, indicating that the sensors are aligned, but the door is stuck open and will not close. ANy ideas here?

Thanks for taking the time to make this.

The red is flashing on the sensor. Green is solid. Voltage is approximately 12 volts on both sides. On the garage door opener itself the little led is flashing red. Help please. [email protected]

Our bathtub does that it’s normal lots of peoples baths do that

WONDERFUL VIDEO PRESENTATION

Great explanation. Nice & simple 👌