Installation guide

Problem Solving
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Cisco 1750 Router Hardware Installation Guide
78-6169-02
Table 4 Troubleshooting ISDN
WIC Symptom Check the Following Possible Solution(s)
ISDN S/T Router is on,
but the OK
LED on the
card is off.
• Is the OK LED on the
router front panel on?
• If no, the router might be
malfunctioning. Contact your
Cisco reseller.
• Are all ISDN cables
properly connected?
• If yes, the ISDN line might be
malfunctioning. Check with your
ISDN service provider.
• Is the NT1 LED on? • If no, the NT1 might be
malfunctioning.
ISDN U Router is on,
but the NT1
LED on the
card is off.
• Is the OK LED on? • If no, the router might be
malfunctioning. Contact your
Cisco reseller.
• Are all ISDN cables
properly connected?
• If yes, the ISDN line might be
malfunctioning. Check with your
ISDN service provider.
• Is the ISDN line
connected to the card
ISDN U port?
• If yes, the ISDN line might be
malfunctioning. Check with your
ISDN service provider.