Digital Equipment DECconcentrator 500, Installation Manual, Page: 74 / 98

Problem Solving 5–5
Table 5–2: Network Management Card Problem Solving
Symptom Probable Cause Corrective Action
Card Fault LED on (red), other
Port Card LEDs off, unit LEDs
are normal. Problem with the Network
Management Card. The card needs to be replaced or re-
paired. Notify your system/network
manager or service provider.
Ring Operational LED off. No network activity, no token
being passed. Indicates a network configuration
problem or problem on the network.
See your system/network manager if
the problem persists.
Port LED off. Port disabled by manage-
ment, LED broken or card at
fault. Set port state on through the man-
agement software; otherwise, use the
reset to default parameter switch. Al-
ways notify your system/network
manager that you are resetting the
parameters.
Port LED blinking red. Unsupported configuration or
ring topology. Verify and reconfigure the cable con-
nections or ring topology. Before you
reconfigure, see your system/network
manager for confirmation.
Port LED blinking green. Unable to connect; no cable
attached. Check the cable connections. Run the
loopback test. described in Section
5.5 to test the port. See Table 5–5 for
problem solving during loopback test-
ing.
Port LED red and card
fault LED off. Link Confidence Test (LCT)
failure, possible cable or
cable connection problem. Check the cable connections. Run the
loopback test.
Port LED red and card
fault LED on. Port broken. The card needs to be replaced or re-
paired. Notify your system/network
manager or service provider.
Port LED alternates red
and green (port A only). Port is in backup state. No corrective action is required. The
backup link becomes active if the pri-
mary link fails.
Controller/backplane Fault LED
blinking RED. Bad UART card. Replace UART card.