3Com 3C16702A manual Problem Solving

PROBLEM SOLVING

The OfficeConnect hub has been designed to aid you when detecting and solving possible problems with your network. These problems are rarely serious; the cause is usually a disconnected or damaged cable, or incorrect configuration. If this section does not solve your problem, contact your supplier for information on what to do next.

Perform these actions first:

■Ensure all equipment is powered on.

■Power each unit off, wait about 5 seconds and then power them on.

Check the following symptoms and solutions:

Power LED not lit. Check your power adapter connection. If there is still no power, you may have a faulty power adapter which needs replacing with another OfficeConnect power adapter. Do not use any other power adapter

with the hub.

Port Status LED yellow for a 10BASE-T port. It is likely that there is a loop in your network which has caused this port to partition. Examine your connections and remove the loop. Each piece of equipment needs only one connection to your OfficeConnect hub. The LED will change from yellow to green, on receiving a valid packet on the port.

Link between two OfficeConnect hubs not working.

Check your hub connections; follow the information given in the “Connecting OfficeConnect Hubs Together” on page 11. With 10BASE-T it is likely that an Uplink/Normal switch is incorrectly set. With 10BASE-2 (Coaxial) it is likely a terminator (end piece) is not properly fitted; this would cause the Coaxial Port Status LED to light yellow (partition).

Alert LED continuously lit. There is either continual excessive use of your network (over 80%) or, more likely, a 10BASE-T port has partitioned due to a loop in your network (in which case the corresponding Port Status LED will be yellow). Examine your connections and remove the loop. Each piece of equipment needs only one connection to your OfficeConnect hub.

Port Status LED not lit for a port that has a connection. There is a problem with this connection. Check that you are using a ‘Straight-through’ cable which is properly connected at both ends, and is not damaged. If the cable is connected to port 16, ensure that the Uplink/Normal switch is set to Normal (out). Also check that the equipment being connected to the hub is powered on, operating correctly and contains the correct type of connection.

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