Teo 8810 ISDN Phone Installation - Manual (Page 45)

13-280118 Rev. C Page 45
Troubleshooting
Inoperable Telephone Recovery Procedures
If a telephone is unable to operate normally or remains locked-up in a particular state:
1. Press the SETUP key; the Setup Menu should be displayed. Select ADMIN, press the ► key, select
RESTART, and then select YES. This will cause the telephone to attempt re-initialization with the
network. If full initialization is achieved, proceed to “Verify operation…”.
2. If the phone display is active, but the Setup Menu does not function, disconnect and reconnect the line
cord or local power supply to cycle power on the phone. If full initialization is achieved, proceed to
“Verify operation…”.
3. If the phone display is blank and there are no lit LEDs, for an 8810T, verify connection to an external
NT1 and verify power connection to the NT1. For an 8810U, verify connection to an external power
supply and make sure the line cord is plugged into the U IN jack on the phone. If power is connected to
the phone, but the display remains blank, replace the phone.
4. If the phone appears operational but full initialization is not achieved, determine which protocol layer is
not initializing by observing the startup diagnostic display.
Layer 1 (L1) does not initialize :
• For an 8810T, locate the external NT1 device for the phone; verify connection between the U (LINE)
connector on the NT1 and the Telco ISDN line. For an 8810U, verify connection between the U IN
jack on the phone and the Telco ISDN line.
• If the external NT1 indicates Terminal Error, verify connection and correct polarity of all wire pairs
between the phone and the S/T (TERMINAL) connector on the NT1. On a multipoint line, verify
correct connections and polarity to the partner phone as well. Verify termination settings on both
phones and the NT1 (see page 9).
• For a standalone or single rack-mount NT1, press the NT1 reset button or cycle NT1 power by
temporarily disconnecting its stand-alone power supply or removing the NT1 from the rack.
CAUTION: If you remove an NT1U-223TC triple NT1 circuit card from the rack, it will disrupt service
to the other two NT1 circuits; plan accordingly.
• The network may take up to 3 minutes to synchronize L1 and L2 with the phone. If there is an
external NT1, verify correct line and terminal status indications on the NT1. Follow additional
troubleshooting procedures in your NT1 documentation.
• When Layer 1 is fully initialized, the display will indicate L1:OK
Layer 2 (L2) does not initialize within a few minutes:
• Repeat Step 1 (restart phone). If problem persists, contact your service provider.
• When Layer 2 is fully initialized, the display will indicate L2:OK and show the TEI number assigned
by the network.
Layer 3 (L3) does not initialize within one minute after L2:OK:
• Verify correct SPID number is programmed and that it is not already in use (on a multipoint line).
• Verify that your service provider has not changed SPID formats or area codes on your ISDN line.
(National ISDN SPID formats include the area code.)
• When Layer 3 is fully initialized, the display will temporarily show L3:OK and indicate the network
switch type before returning to the normal idle display.
Verify operation of the phone after full initialization:
1. Go off-hook on an idle line. The selected key should light green and you should hear dial tone.
2. Dial a valid directory number for a test call. Verify that the call is successfully completed.