Hard Shutdown (two back to back obstructions) LED blinking, Buzzer sounds for 5 minutes 936 control board February 14, 2020 22:46 Updated Clear any obstructions from the path of the gate. Press RESET to clear (or hard reset button). Related articles Box Detectors, Inside Obstruction, 24VAC Wiring Diagram (ALE1) alert 1: gate forced open