NEC Univerge SV8500 Operation And Maintenance Manual page 669

<<For Single Configuration>>
<<Check by replacing the MUX circuit card.>>
(1) After replacement of the MUX circuit card, make a station-to-station call in the faulty unit and see if speech
is normal.
(a) Replace the MUX circuit card by referring to
plexer) Circuit
<<Check by replacing the TSW circuit card.>>
(2) After replacement of the TSW circuit card, make a station-to-station call in the faulty unit and see if speech
is normal.
(a) Replace the TSW circuit card referring to
Switch) Circuit
(3) Check the line/trunk circuit cards mounted in the unit to see if they are faulty.
(a) Set the MB switch of the line/trunk circuit card UP and extract it from its mounting slot.
(b) Make a station-to-station call and see if a fault occurs.
(4) Perform this check on an individual basis.
(a) If the fault has stopped, the circuit card extracted at that time is faulty. Replace the circuit card with a
spare.
(b) If the fault continues, check the next circuit card.
Card.
Card.
CHAPTER 5 Operation Procedure for System with PIR
Section 1.5, Replacement Procedure of MUX (Multi-
Section 1.7, Replacement Procedure of TSW (Time Division
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