– 599 –CHAPTER 5 Operation Procedure for System with PIR3.1.3 Line Fault - When DT Cannot Be HeardNote: If a circuit card is replaced because only one line is faulty, no other lines in that circuit card can be useduntil the replacement is complete.(1) When OPE lamp on the LC circuit card does not illuminate.(a) Confirm MB switch of the LC circuit card is in ON position (UP).(b) Use ASDT command to confirm that station data in the LC circuit card is assigned.(c) Replace the LC circuit card with a spare.(2) When BL lamp for each line is flashing or illuminating on the LC circuit card(a) Confirm MB switch of the LC circuit card is in ON position (UP side).(b) Use the MBST command to confirm LC circuit card has not been placed into make-busy state.(c) Use the ASDT command to check the station data assignment.(d) Replace the LC circuit card with a spare.(3) Check the faulty line on the MDF.(a) Isolate the faulty line to the in-house wiring side and to the system side.(b) Connect the test telephone to the system side and check to see if dial tone can be heard.[When Dial Tone (DT) is heard]• Check the in-house wirings.• Replace the station telephone set with a spare.[When no DT or side tone is heard]• Check LT cables.• Replace the station telephone set with a spare.[When DT is not heard, but side tone can be heard.]• Replace the LC circuit card with a spare.
