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Electronic Theatre Controls Inc

What do the LEDs on a CEM+ mean?

The LEDs on the CEM+ control board give general information regarding chip status, network status, or airflow status.

LED and Color Indicator Meaning
CR3 - Red CPU status - U27 Not useful for in-field troubleshooting
CR4 - Green CPU status - U27 Not useful for in-field troubleshooting
CR5 - Green Network Speed On - 100Mb/s
Off - 10Mb/s
CR6 - Yellow Network Transmit Network Transmit Status
CR7 - Green Network Link Network Good Link Status
CR8 - Red Network Collision Network Collision Status
CR9 - Yellow Network Duplex Network Duplex Status
On - Full Duplex
CR10 - Red DSP status - U35 If blinking rapidly, indicates the DSP is not loaded. Check Phase A for correct voltage
CR11 - Green DSP status - U35 Not useful for in-field troubleshooting
CR13 - Green Airflow Indicator

On indicates good airflow. Outputs will function

Off indicates bad airflow. Low Airflow error. Outputs will not function or may function intermittently

If all the network LEDs are off, this may indicate problems with the Ethernet cable or network connection to the rack or backplane. If the Ethernet cable tests OK, the PHY network chip on the CEM+ may have failed

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