3Com 3CBLSG48 User Manual page 209

198 A D T
PPEnDIX : ROUBlESHOOTIng
Table 12 Troubleshooting Solutions
Problems
Device is in a reboot loop
no connection and the
port lED is off
lost Password
Possible Cause
Software fault
Incorrect ethernet cable,
e.g., crossed rather than
straight cable, or vice
versa, split pair (incorrect
twisting of pairs)
Fiber optical cable
connection is reversed
Bad cable
Wrong cable type
Solution
Download and install a working or previous software
version from the console.
Check pinout and replace if necessary.
Change if necessary. Check Rx and Tx on fiber optic cable.
Replace with a tested cable.
Verify that all 10 Mbps connections use a Cat 5 cable.
Check the port lED or zoom screen in the nMS
application, and change setting if necessary.
Contact 3Com