This is almost certainly an electronics problem.
Garage door opener goes down but not up.
Garage door starts down then stops and goes back up or safe t beam system malfunction.
If it is a new installation check the postion of the door arm.
There is one on each side of the door.
Try making small adjustments.
Make sure only the safe t beams that came with this garage door opener are installed.
Now put a step ladder under your garage door opener and climb it.
Check if the limits are properly set.
Now point the safety sensors at each.
However if your garage door doesn t bounce back up then you know you have a problem.
If the door then goes down when you press the button hit the button again before the door hits the ground and see if it goes up.
There is a latch in the circuit that keeps the down motor on until the lower limit switch is tripped.
This brain can wear out in time so you could need a replacement.
Get logic board replacement.
They both have lights and both lights should be on.
Try opening the garage door with the remote and see what happens.
Two things stop the lower direction travel of an overhead door.
Now it may be the lower limit switch itself but it s more likely to be a relay or ic problem.
It s important to get this switch at just the right distance from the motor so that the door is able to close all the way but the motor also knows to stop running.
If the door goes up but you can t make it go down you probably need to adjust the sensors.
You ll then want to test it again and if it s not right keep adjusting the down limit nob until your garage door hit the board and bounces back up.
Check if the safe t beams red led light is flashing.
Other things could be wrong but they are in the weird category.
This is related to the up limit switch.
Connect the white wire from the sensor to the white terminal of the garage door opener and then the black and white wire to the grey terminal.
Adjust the limits as needed.
Now press the remote control.
T his is a pretty uncommon problem but one that can happen after you ve first installed your garage door opener.
Go along with your safety reversing sensors.
If your garage door hits it bounces up and starts to open again your garage door is working well.
Disconnect the pre wire from the garage door opener.
To reconnect the garage door to your liftmaster garage door opener manually close the garage door pull the emergency release handle down.
To fix this issue increase the down limit one quarter turn.