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8-4 CHAPTER 8: TROUBLESHOOTING
communicate at incompatible baud rates. Refer to
“Evaluating Symptoms and Solutions” below.
Monitoring the DTR LED
When illuminated, the Data Terminal Ready LED indicates
that communication between the 3C882 ISDN modem and
your computer has been established.
If the DTR LED does not illuminate, refer to “Evaluating
Symptoms and Solutions” below.
Evaluating Symptoms and Solutions
Table 8-1 lists symptoms of common problems, possible
causes, and possible solutions.
Table 8-1 Symptoms, Causes, and Solutions
Symptom Possible Cause Solution
TEST LED remains
lit for more than a
few minutes
An internal failure. Notify 3Com Technical Support that
the 3C882 ISDN modem has failed the
self-test.
D channel remains
lit for more than a
few minutes
Poor physical connection to
the local telephone company.
If the telephone wires at your site
appear to be satisfactory, call your
local telephone company for repair of
telephone company equipment and
troubleshooting assistance.
D channel
continues to flash
for more than a
few minutes
A mismatch between the
settings of the ISDN line and
the 3C882 ISDN modem
configuration.
Verify the telephone number and SPID
(if required). If the D channel LED
continues to flash, open the 3C882
ISDN modem’s Configuration dialog
box. If your telephone number has
changed, the SPID Wizard may be able
to reconfigure your SPID values. Or call
your telephone company to verify the
SPID and telephone number and
ensure that the telephone company
has configured the ISDN line properly
(refer to Appendix A, “Ordering ISDN
Service.”).
(Continued)