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AssuredElectrical, Home Specialist
Category: Home Improvement
Satisfied Customers: 4241
Experience:  35 years home improvement
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I have a marantec 4500e garage door opener and I have about

Customer Question

I have a marantec 4500e garage door opener and I have about 2 volts going to the safety sensors. Not sure if the problem is with the power board or the logic board.
Submitted: 2 years ago.
Category: Home Improvement
Expert:  AssuredElectrical replied 2 years ago.

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

Please elaborate on the situation.

What is happening with the door opener?

Will not open or close?

Partial movement?

Details will help to evaluate what the problem may be and what is needed to correct.

Let me know and we can continue,


Customer: replied 2 years ago.
The door opener will only operate from the wall button. I have to keep the button pressed to close the door. When it closes the light flashes on and off and I get a problem code of 7&8 which indicates a safety sensor problem. The sensors have about 2 volts at the sensors and no lights. I checked the sensors with an ohm meter and they show resistance. I also checked them with a 24 volt supply and the lights came on. I'm not sure which component supplies the operating voltage to the sensors so I'm not sure what part to replace or what else to check.
Expert:  AssuredElectrical replied 2 years ago.

Ok, thanks.

Need to get the sensors connected back to the opener wiring and then see if one or both eyes have the LED lit.

Then we can see which direction to go on the troubleshooting.

You may remember, if so post the original findings, please.

Let me know what the status of the sensors is when all connected.


Customer: replied 2 years ago.
Neither sensor has a light. There is not enough voltage to light the LEDs or to operate the sensors. I also checked the transformer voltage at the opener and it has 24 volts.
Expert:  AssuredElectrical replied 2 years ago.


It is unknown what type of voltage is used for the sensors, as they do no switching, as is usually thought No publications for what voltage a manufacturer applies to the sensors, the sensors output a variation frequency to the logic board in operation.

Everything works off the same power supply and if the opener works with the wall button to over ride the sensor failure, the issue will be in the sending eye , as it has to illuminate before the receiving eye can function.

You can ohm out the wiring to the opener head from the sensor with them disconnected at each end and if the wires are good, a new set of eyes will be needed as they only sell them in pairs.

Customer: replied 2 years ago.
I tried the sensors on my other garage door opener and they operated correctly. I have about 14 volts feeding the sensors on the door opener that is working correctly and 2.4 volts on the opener that is not working correctly. What I need to know is how to determine which component to replace.The logic board or the power supply board.
Expert:  AssuredElectrical replied 2 years ago.


Since they do not publish a detailed wiring diagram for the openers, the easiest way to determine if the eyes go directly tot he power supply or the logic board

is to verify where the wires go on the black side of the photo eye terminals.

Most go to the Logic board, and that is what I would suggest, but not knowing exactly yours, I suggest to double check.

Looking at the parts for the opener, there is only one board, the other is a transformer.

Transformer can be checked if it has a labeled marking on the voltages.

The logic board can also do other things with that signal and why it would be the high suspect.

See below on the parts