Locating DMX Chips on a CEM+

Situation 

DMX A and/or DMX B does not seem to be working correctly in my Sensor+ rack and I would like to swap the DMX chips for further testing. 

Description 

Depending on the age of your CEM+, the design of your PCB may differ from the example below. 

Solution 

1. Power off the rack.
2. Use the springloaded handle to remove the CEM+ from the rack
3. With the LCD screen and buttons toward you, locate the upper left-hand corner of the PCB to the right of the transformers
4. DMX A and DMX B will be located here
   1. Silkscreen labels may appear as "U6" (DMX A) and "U5" (DMX B)*
5. Locate the SPARE DMX chip to the left of the gray ribbon cable, next to the yellow battery
   1. Silkscreen label may appear as "U43" (SPARE)*
6. When swapping, align chips based on the indent indicating pin 1

*If you have an earlier CEM+, you'll notice there will be additional TX and RX chips. Replace both the regular chip and TX or RX based on what that port is set to do. Their labels are as follows:

• DMX A TX (opto)- U3
• DMX A  RX (opto)- U8
• DMX A - U6
• DMX B TX (opto)- U1
• DMX B RX (opto)- U7
• DMX B - U5

Related Documents 

Sensor CEM+ DMX Driver Replacement Instructions RevA 2009.pd