4 - 2 ONline Ethernet 10BASE-FB Module Installation and Operation Guide
Troubleshooting Using the Port Activity LEDs
If a port Activity LED does not light, use Table 4-1 to help troubleshoot the
problem.
Table 4-1. Troubleshooting Us ing the Port Activity LEDs
LED
State Possible Cause Corrective Action
Off There is no traffic received
from the segment. None.
Port is disabled. Use the EMM to check if the
port is enabled or check the port
dip switch setting.
Power is off. Check the Controller Module
Power LEDs.
Activity LED has burned
out. Press the LED check button on
the Controller Module.
10BASE-FB Module port is
faulty. Connect the cable to a different
port.
10BASE-FB Module is
faulty. Try a different 10BASE-FB
Module.
Backplane connection is
bad. Reinsert the 10BASE-FB
Module. If this fails, try another
concentrator slot.