Skip to main content
Electronic Theatre Controls Inc

Control Module (CEM) Powers on but Not All Dimmers Work in Sensor Rack


The control module in my Sensor Classic (CEM), Sensor+ (CEM+), or Sensor3 (CEM3) rack will power on, and some, but not all of the dimmers will turn on.

Explanation of Issue

This could be a configuration issue, or there are several things to check in the hardware.


  1. Check the configuration. Generate defaults if necessary. See the links below for instructions on how to generate defaults on rack type below.
  2. With the rack powered off, make sure the control module is fully seated in the backplane. Take the palms of your hand and firmly push on both sides of the control module together. If it's not fully seated you will feel it shift backward and hear a click. Power back on and test your system.
  3. Power off the rack, and remove the CEM and several modules. Inspect the ribbon cable connections on the rear of the backplane, as well checking the cables themselves for knicks, holes, tight crimps, or other oddities that may cause the ribbon to not pass data. Also check the other end of the cables where they plug into the signal distro cards.


  • Was this article helpful?