3com 3CNJ90 사용자 설명서

Appendix E: Troubleshooting the NJ90

If you encounter problems with the NJ90:

1. Verify the NJ90 is receiving power by viewing the Power LED (it

should be lit). If the Power LED is not lit, make sure:
• The other end of the network cable is plugged into a system

that provides Power over Ethernet according to IEEE 802.3af,

if using Power over Ethernet.

• The Local Power Supply is plugged into the NJ90 and into a

working electrical outlet, if using Local power supply.

2. Verify the NJ90 is connected to the network properly by viewing

the Link LED (it should be lit). If the Link LED is not lit, make sure

the network cable:
• Is terminated properly. Refer to the connector manufac-

turer’s instructions for terminating the cable. Be sure to test

the connector and verify it is working.

• Has a valid connection to the network.
• Adheres to proper length and cabling specifications for your

network.

3. Make sure the port on the switch to which the NJ90 is connected is

configured as a standard MDI-X port. Make sure all cables con-

necting the NJ90 to the patch panel are straight-through cables

(not crossover cables).