DMH E-cutout Won't Open
 

My symptom was that although I could hear the motor engage the butterfly would not open without the assistance of pressure using my finger. I removed the unit and soaked the plate/butterfly with WD-40 to let it sit overnight. This action did not help. After a brief search I saw many topics of the butterfly being stuck open due to o-ring issues but none with the symptoms I was experiencing with the butterfly remaining closed even though I could hear the motor engage. I investigated what could be causing the flap from opening and noticed that plate was loose from the motor housing. After removing the motor housing both torx screws were loose but one was backed out a few turns as seen in the pics. I removed them for cleaning and added a small amount of blue loctite. I reassembled the unit and it works properly.