Table 5–4 (Cont.) Troubleshooting a DECrepeater 90FA in a DEChub 90
Backplane
If...
Then...
Do this...
If all port status LEDs do light
momentarily, the ports should be
reconnected one at a time.
Reconnect each fiber port
receive channel. Note
that the external device
will not be receiving the
idle signal and should
not be transmitting
data; therefore, the port
fiber-link and status
LEDs should light as
each receive channel is
connected.
If the fiber-link LED lights and
the port status LED does not
come on
Reconnect the receive
channel of a different port
on the repeater.
If the fiber-link LED lights and
the port status LED fails to light
Ensure that the external
equipment is operating
properly. Connect the
transmit channel of a
known good device to the
receive channel of the
ports in question.
If the fiber-link LED lights and
the port status LED remains off
Check that the repeater
network activity LED is
on. An unconnected port
will be segmented and will
require good data to be
transmitted before it is
unsegmented. Connecting
the receive channel of
a port should establish
the link; however, a good
packet of data must be
available for transmission
to unsegment and return
the port to normal status.
If the fiber-link LED lights and
the port status LED remains off
while the repeater activity LED
is on
Replace the repeater.
(continued on next page)
Troubleshooting 5–11