User's Manual Part 2

PN 8100-40 Help Hot Line (U.S. only): 1-800-530-9960 10-7
620004-0 Rev. E
Troubleshooting
7. The Expansion Hub is not properly receiving the synchronization signal from the
Main Hub.
Too much loss on downlink MMF. Might be due to MMF pairs not attached to the
proper connector.
a. Check that the “down” cable end is in the DOWN port connector on both the
Main Hub and on the Expansion Hub. Same for the “up” cable end and con-
nectors for the
UP port.
b. If the problem persists, check the integrity of the MMF cable using an Optical
Time Domain Reflectometer. If the fiber is faulty, replace it.
c. If the MMF cable is OK, try using a different Main Hub port.
d. If the problem persists, replace the Main Hub.
e. If the problem persists, replace the Expansion Hub.
8. The Main Hub is off.
• Make sure the power cord is connected to a live AC power jack and that the
Main Hub power switch is in the on (
1)position.
9. Main Hub is not properly generating the synchronization signal.
• Turn off the Main Hub and then turn it back on. If the unit functionality
SYNC
LED stays off, the Main Hub requires replacement.
10. The Expansion Hub is not properly sending the synchronization signal to the
Main Hub.
• The MMF cable connection might not be good, or if the system was working,
the MMF uplink cable is pulled out or cut.
11. The RAU is off.
• Check that the UTP/STP cable is operating properly.
– Check that the UTP/STP cable has been properly crimped and passes a stan-
dard TIA/EIA 568-A Cat-5 compliance test.
• If the system was working, the UTP/STP cable is pulled out or cut.
12. There is excessive optical loss in the uplink direction between the Expansion Hub
and the Main Hub.
• Verify that the optical loss in the uplink fiber does not exceed 3 dB optical.
• Check the fiber ports for debris and clean if necessary.
• The Main Hub MMF port may be faulty.
– Move the fiber to another port.
• The Expansion Hub may be faulty.
13. A Cat-5 cable has been disconnected and moved to a new port. The Expansion
Hub’s port disconnect memory has issued an alarm.
• You must cycle power to the Expansion Hub to clear the memory and the
latched alarm.