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