Defective Line Card; Defective Ds-1 Link - Nortel DMS-100 Series Maintenance Manual

8-4 Trouble isolation and correction

Defective line card

If one card failure occurs during the line card diagnostics test, the failure
causes failure of the whole LCM unit. The defective card can be dificult to
locate. Two procedures are available which maintenance personnel can use
to locate the defective card.
Perform procedure 1 during a maintenance window to avoid possible service
interruptions. Technicians with experience can perform this procedure with
precautions during busy service periods.
Procedure 1
Find the vertical connection to the LCM in trouble. Use Table MTAVERT.
Use a buttset with caution on the backplane of the MTADRIVER.
Operating company personnel can hear one of the following:
Procedure 2
Access the line test position (LTP) level of the MAP display. Post any line
equipment number (LEN) located on the defective LCM.
Put a tone on the posted LEN. Go to the mainframe with the buttset and
listen to all other LENS on the LCM.
Note: Operating company personnel locates two LENS with tone. One
LEN is the LEN first posted at the LTP level. The second LEN is the
defective line card.

Defective DS-1 link

To handle a defective DS-1 link:
1 Post the RLCM.
2 Determine if fault indicators are present.
3 Display the central side (C-side) links.
297-8381-550 Standard 02.02 April 1999
dial tone—Operating company personnel draw a dial tone from a 6X21
card. Dial the operator. Ask for the line number you are on. This line
number is the defective line.
talk battery—If possible, hook up a proprietary telephone and call the
operator to determine which directory number (DN) is now in use.
Perform procedure 2 during a maintenance window to avoid possible
service interruptions. Technicians with experience can perform this
procedure during the day if precautions are taken.