Skip to main content
Electronic Theatre Controls Inc

Locating DMX Chips on a Paradigm Architectural Control Processor (PACP)


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


Depending on the age of your PACP, the silkscreen labels on your PCB may differ from the example below. It is also possible that labels "DMX A," "DMX B," and "SPARE" will appear on the PCB next to the appropriate chips. 


  1. Unscrew two small Phillips screws in the back of the PACP to remove the lid
  2. With the LCD screen and buttons toward you, locate the upper right-hand corner of the PCB
  3. DMX A and DMX B will be located here
    1. Silkscreen labels may appear as "U42" (DMX A) and "U46" (DMX B)*
  4. Locate the SPARE DMX chip to the left of DMX A and DMX B
    1. Silkscreen label may appear as "U10" (SPARE)*
  5. When swapping, align chips based on the indent indicating pin 1

*If you have a gen 3 PACP, DMX A is on U4, DMX B is on U5, Spare is on U1.