Kwikee Stairs failure rate

I am just throwing this out there, always wait till the steps are fully extended before stepping on them otherwise you are putting strain on the motor, gears and arm when you add body weight to it. That won’t cause the failure of a control board, but could be the reason for the motor and gear failure.

My guess on your intermittent issue is a sensor, wire issue. Corroded (Broken) wire to the door sensor, or as was mentioned bad ground.