3Com 3C13840, 3C13880 Chapter 7 Troubleshooting

3Com Router 6000 Family
Installation Manual
Chapter 7
Troubleshooting
3Com Corporation
7-1
Chapter 7 Troubleshooting
7.1 Troubleshooting the Power System
Symptom:
The RUN LED on the PSU is OFF or blinking.
Solution:
Check that:
z The power switch on the router is turned on.
z The switch of the power source is turned on.
z The power cord is correctly connected.
z The power source meets the requirement of the router. If the PSU is DC-input,
check the AC/DC OK LED: solid ON means the input voltage is normal (85 to 264
V), off means the input voltage is abnormal.
7.2 Troubleshooting the Configuration System
If the router passes POST after powered up, the console screen displays the startup
banner; if faults occur to the configuration system, the console screen displays nothing
or only illegible characters.
Symptom 1:
After the router is powered on, the console screen displays nothing.
Solution:
Step 1: Check that:
z The power system is normal.
z The console cable is correctly connected.
Step 2: Check the console cable and the terminal (HyperTerminal for example)
settings.
Symptom 2:
After the router is powered on, the console screen displays illegible characters.
Solution:
Verify that the terminal settings are as follows:
Baud: 9600