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Electronic Theatre Controls Inc

CEM3 Reporting Over-voltage, Under-voltage, and Frequency Errors


The CEM3 is reporting frequency and/or phase voltage errors
Errors may include conflicting information, i.e. Phase voltage high, Phase voltage low, Phase no voltage

Explanation of Issue

For errors with a single phase problem, such as Phase C voltage low, a phase op-amp, diode, resistor, or opto-isolator may have failed.

For errors with conflicting information, the DSP may have a problem. Either the DSP is not loading the firmware, or the DSP has been damaged. Phase A might be missing between the mains line and the DSP, suggesting an op-amp, resistor, opto-isolator, and/or diode failure

This typically cannot be fixed in the field


If all phases read OK going into the rack test OK, please contact ETC Technical Services to begin the RMA process


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