20 Most Recent Chamberlain 3/4-HP Power Drive Chain Drive Garage Access System Questions & Answers

Something in the drive is jammed preventing the motor from spinning. Correct the problem lest you will burn out the motor if allowed to hum and overheat.

Check the wiring to the sensors and ensure that it is connected properly to the opener, and that there are no breaks or cuts in the wire, and that no staples have shorted the wires. After that, be sure the lenses of the sensors are free of dirt and debris, and they can clearly see each other. If the problem persists, replace your sensors.

Check your manual and re-program the up/stop and down/stop position. Also make sure the new trolly is in it's proper position.(in the closed position) Hope this helps

http://www.chamberlain.com/doityourself/pdfdocs/114A3282.pdf

Please find your user manual above, for reference..
Most likely you have had a controller or drive failure? either that or a sensor has failed?, one simply must troubleshoot each section to tell. It is impossible to diagnose without actually testing the unit.
You need to see if there is drive to the motor, as it hums i suspect there is? but obviously something is preventing it from working, only a loss of drive or command to do so can cause this. It maybe the Microprocessor not "Telling" the motor to operate F/R. But it also may be a sensor preventing it from working, accordingly check all sensors. Also the motor too, as even though it "hums' it still maybe faulty, perhaps a shorted winding etc, testing the motor with a meter will tell you if it is faulty or not, the motor should have a lowish, resistance reading across the terminals, remove power first, to measure.
If you wish to DIY, then first one must obtain a service manual, I have searched but have been unable to locate one? Using said manual one then must perform the troubleshooting steps to locate and isolate the faulty component, with a view to replacement, and using the same manual glean the parts numbers and purchase the components.
It may indeed be better to call in a professional to at least first only give you a "Quote" as to whats wrong and potential costings? At least then one is appraised of things and one can then "go from there" as to what to do, repair or replace?

Normally this means that either your transmitter needs to be reprogrammed or you may have loose wiring. OR the alternative is that one of your sensors could be dirty or misalligned and you might not know it. Check the users manual and your door buttons to see if any wiring is faulty or loose. Most of the time it has to do with sensors. Holding button down is a manual bypass to force the door to go down. Something is telling it to stay up. Check your sensors. They can be easily moved, jarred, or knocked loose by accident.

If working with remote and/or keypad check wire from opener to doorbell/push button/wall controller. Rami orangedoors.com

Question edited for clarity. This is an older model. Either the weight of the door is borderline for the motor and that is why it is beeping. The counterbalance system need adjusting. Or the carbon brushes on the motor need replacing. You can also try lubricating every single item that moves and the tracks to reduce rolling and sliding resistance. Use proper garage door spray or light machine oil not WD40 which goes waxy / gummy after a couple of months. https://www.google.com/search?q=Coromaster+B2B+garage+door+opener and https://www.google.com/search?q=Coromaster+B2B+garage+door+opener+opens+halfway and Beeps https://www.google.com/search?q=Coromaster+B2B+garage+door+opener+motor+beeps ..

Question edited for clarity. It doesn't look like that model number is correct 390 is the frequency of the signal. It is mentioned here are part of the regulatory approval process as a much longer number https://fccid.io/B8QOHDH390 The Learn Button is next to the bulb https://www.geniedoor.com/support/programming-instructions/garage-door-opener-remote-programming/ More here https://www.geniedoor.com/support/programming-instructions/ https://www.google.com/search?q=genie+receiver+ohdh390+learning+manual ..

Sounds to me like a cold solder joint on one of the boards

A concrete mixture ratio of 1 part cement, 3 parts sand, and 3 parts aggregate will produce a concrete mix of approximately 3000 psi. (20685 kpa)

check safety sensors located near floor on both sides of door.

Unlikely your garage door is battery operated. The remote and wall unit yes. The remote just tells the mains operated motor to get turning. The issue will either be that everything that moves needs lubricating, motor spindle, pulleys, chain, tracks and pivots, or the carbon brushes in the motor need replacing. https://www.google.com/search?q=DTS+600+garage+door and how to fix https://www.google.com/search?q=DTS+600+garage+door+opens+slowly ..

Question edited for clarity. Question moved from Cars and Trucks category. Look at the corners of the doors that hold the aluminium frame together and if it is a modular door, tighten them up. If it is a solid door, adjustment can be made by shimming behind the bottom hinge with a piece of cardboard. This will move the bottom out and up. ..

Look at this video, it should answer your question. The learn button in under the green button. Remove the green button. http://www.youtube.com/watch?v=7CqMy2UfG9k

Check the opening limit dial on the garage door opener unit. You can locate the dial that controls the opening limit on the opener unit and use a flat head screwdriver to turn the dial counter clockwise until the door stops about an inch and a half away from the stop bolt. Then, test the door and make sure it does not slam into the bolt. A video tutorial on how to adjust the opening limit of a Craftsman garage door opener is available on YouTube. If the above step does not work, check the limit switches on the garage door opener. Most garage door openers have limit switches that control how far the door opens and closes. Improperly adjusting these switches can cause the door to stop halfway. Consult your garage door opener's manual to learn how to adjust the limit switches. Make small adjustments until the door closes fully. Craftsman garage door opening too far and hitting stop bolt easy adjustment (youtube.com)

Check this out to reset.... https://www.youtube.com/watch?v=YzAe--sV_h8 Best to you.