R_O_M
Guest
The micro switch that triggers the concave door alarm is on the right hand side and is triggered by the extended locking collar screw on the concave door shaft. This shaft is the one you put the handle on to close the concave door. The locking collar may have come loose or slipped which will not place the extended locking screw in the right place to trigger the micro switch. The collar is usually fairly fussy to set up to get the right position to trigger the micro switch.