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Electronic Theatre Controls Inc

MPE DMX IC's (U2, U3)


The information in this post is provided to assist in troubleshooting. Perform work at your own risk. ENSURE ANY POWER FROM DEVICES HAS BEEN DISCONNECTED BEFORE SERVICING ANY EQUIPMENT. If you do not feel comfortable performing the work, please contact us or your local service center. Be aware that ETC and its Affiliates are not responsible for any damage or injury caused by service of our products by anyone other than us or our authorized service providers, and such damage is excluded from the product’s warranty.

Both U2 and U3 must be functioning for the MPE to receive DMX.

  • U2 (Originally Z216 (75176), replaced by Z1458-F) receives the signal first in the DMX input circuit.
  • U3 (Z423) is the 6N137 optocoupler that is in line next after U2.

If the MPE has a daughter card (not MPE-DMX512 (7050A1015-1):

U1 (Originally Z216 (75176), replaced by Z1458-F) on the daughter card (7050B5017) can be placed in U2 on the CPU board (7050B5015) for troubleshooting DMX reception.  U1 on the daughter card is for receiving AMX, which is not as common as DMX.

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