Liftmasterproblem

Help,

I have a liftmaster opener and it clicks then hums without opening or closing, although it would go up and down after maybe 5 or 6 times of pressing the remote. The learn light flashes 5 times and I have replaced the logic board. The capacitor doesn't look discolored or any deformity on the casing. I would bang on the motor when I pressed the remote button and it would move the door in either direction, but that has now stopped. What's your thoughts?

Have you taken the cover off of the operator and looked inside? It sound like the gear assembly may be worn. If the gear looks ok then you may want to check the RPM board. The connecting wire to it could be loose or it may have just failed.