Only one Cooler Module has communication problems.

1. Check external data cabling from projector to Cooler Module. Ensure that all thumbscrews are fastened.

2. Check Cooler Module internal data connection on Controller board (reference 9, image).

3. Malfunction Controller board of the Cooler Module. Replace Controller board. See service procedure "Replacing the Cooling Unit control boards".

4. If the problem persists, replace the Cooler Module. See service procedure "Replacement of a Cooler Module"

All Cooler Modules have communication problems. Malfunction LCB

1. Replace the LCB. See service procedure "Replacement of the Laser Control Board".