What was found
MAIN DOOR: MAIN ENTRY DOOR IS OPEN WITH THE BOTTOM STEP EXTENDED AND WILL NOT CLOSE. AUTO FUNCTION WILL NOT WORK. CANNOT BE ACTUATED BY EITHER INTERIOR SWITCH OR EXTERIOR SWITCH (MANUAL OR AUTO). WHILE ATTEMPTING TO MANUALLY CLOSE THE DOOR WITHOUT THE MOTOR ASSIST, WE COULD NOT RETRACT THE BOTTOM STEP. IT APPEARS FROZEN IN THE EXTENDED POSITION. THEREFORE, THE MAIN ENTRY DOOR CANNOT BE CLOSED. CORRECTIVE ACTION: REPLACED DOOR ACTUATOR. OPS CHECK GOOD. IAW BOMBARDIER GL-6000 AMM 52-11-25