Nortel Meridian 1 Planning, Installation And Operating Instructions page 550

Possible cause
Incorrectly
programmed
Defective telephone
Defective PE circuit
card
Defective wiring
Defective Digitone
Receiver
Excessive Digitone
traffic
Option 11C Compact
Chapter 25 — Fault locating and clearing
Action
To determine the correct Class Of Service (CLS) use
LD 20
PRT
If CLS is DIP, change to DTN using
LD 10
If only one telephone is affected, replace it.
If there is still a telephone problem, go to the next possible cause.
Replace the affected circuit cards.
Enable the circuit card by entering
LD 32
ENLS s
(s represents the shelf number; 0 for the main cabinet, 1 for the
expansion cabinet.)
Test the circuit card by entering
LD 30
TEST
If only one telephone is affected, make sure wiring is properly
connected and wires are not interchanged, crossed, or grounded
Check the wiring between the telephone and the cross-connect
terminal
Check the wiring between the PE shelf and the cross-connect
terminal
If there is a wiring problem, correct it.
If there is still a telephone problem, go to the next possible cause.
If the condition is intermittent or more than one telephone is affected,
test the Digitone Receivers in the NTMW01 SSC card by entering
LD 34
DIS 0 and ENL 0
Replace the NTMW01 SSC if it fails the test.
If there is still a telephone problem, go to the next possible cause.
Planning, Installation, Fault Clearing and CCBR Guide
Page 531 of 536