A: 1. First check the fuse on the monitoring board (17001-03465) to see if it is blown. This is the most common direct cause of this fault.
2. If the fuse is normal and a spare SNMP module is available on-site, replace the SNMP module directly and observe whether the indicator returns to normal.
3. If both of the above are normal, the fault is most likely in the connection cable between the SNMP module and the monitoring board（J16）.

Preventive measures:
1. During operation, ensure the SNMP module is connected to the port marked “Network”.
Incorrect connection to the “COMM” port may cause faults such as blowing the fuse on the monitoring board.