Troubleshooting help: Three I-Cues lost DMX signal


Hi folks,

Looking for some suggestions to troubleshoot a loss of signal on my Icues.

I've got 3 I Cues that have all stopped receiving DMX within the space of 2 weeks. The current home run from the power supply is connected to 2 Icues and 2 DMX Irises. When I've lost the I Cues, the home run will still transmit DMX to the irises. The problem seems to be that the PCB is failing. I replaced the PCB in one of the ICues that failed, and it is now working fine. I'm worried though that something else is going on given the timing of so many failing at about the same time. I believe that all three ICues are about the same age, but I don't know that for sure.

The current setup is one I've used many times in the past without any issues. The power supply is also running 7 Forerunners, so we are well within the power limits of the power supply (2x 200w "channels"). My power supply doesn't allow a return run from the end of the chain, but I do have a terminator at the end of the line. I've currently isolated the 2 ICues I'm using on their own power output of the power supply, and each ICue is on its own home run now.

Has anyone else experienced a failure like this? Is there anything that would be worth checking from the power supply side of things to see if they are being burned out somehow?

Apologies if I'm lacking some clarity.


Well-Known Member
Fight Leukemia
If the units show the proper display during boot up, and the controls work normally, then try replacing the 75176 transceiver chip. It's the DMX data input. It wouldn't be the first time that some kind of transient killed off several of those chips. They seem to be vulnerable to damage.


Well-Known Member
A few years (6?) ago I had an I-cue stop receiving DMX as well. I had the SMT DMX chip replaced and that did not solve the problem. The replacement cost of the whole PCB at the time was astronomical, almost the cost of a new unit.
The price of one of those has gone up tremendously since then.

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