When an controller needs to be hard reset for a variety of reasons (System LED is off, LEDs are solid, various other conditions) there is a simple fix to hard reset the controller to see if it can come back online and work efficiently.
Resetting an Mx-1 or Mx-1-ME
Power down the controller
Remove the circular battery on the controller for one minute
Re-insert the battery into the controller
Power the controller back on
View operation
Resetting an Mx-4/8
With the system powered on, press and hold the blue button in the bottom left of the controller for:
1 second: cancel alarms and clears the event buffer
3 seconds: resets the tamper switch
30 seconds: cold restart (reset to factory defaults)
View operation