my idrive is jammed

by Joe
(Windsor, Canada)

My pivot arm on my wayne dalton idrive is jammed in the up position. When the door closes the motor makes a humming noise attempting to lower the arm, but the arm is stuck there.

I already tried to adjust the detent pin by turning it clockwise. Is there a way to fix the arm so that it lowers again? Perhaps by disassembly and then reassembling?