NEC UNIVERGE SV8500 - Unit Fault - ACT-Side MUX Card Is Faulty and System Has Changed over

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CHAPTER 5 Operation Procedure for System with PIR
4.4.5 Unit Fault - ACT-Side MUX Card Is Faulty and System Has Changed Over
Faulty Situation:
• The ACT side has become faulty and the system changeover has executed in the dual configuration system.
•[4-S] MUX Ready Failure / [4-T] Both MUX Failure
[23-Y] MUX Clock Failure
(1) Check to see if the MUX circuit card of the STBY side is making poor contact.
(a) Set the MB switch of the MUX circuit card UP.
(b) Extract the MUX circuit card from its mounting slot and clean the contact portion. If cleaning cannot
be done, repeat insertion and extraction of the circuit card two or three times.
(c) Set the MB switch of the MUX circuit card UP and insert the circuit card into its mounting slot.
(d) Set the MB switch of the MUX circuit card DOWN.
(e) Set the faulty system to ACT side referring to How to Control Switching Block
in Chapter 2.
(f) Check to see if a station-to-station connection can be set up within the faulty unit.
(g) If the connection cannot be established, change the faulty side to ST-BY and repeat the above proce-
dure to the spare MUX circuit cards.
(2) Replace the MUX circuit card with a spare, and check it.
(a) Replace the MUX circuit card referring to Section 1.5, Replacement Procedure of MUX (Multiplexer)
Circuit Card.
(b) Place the MUX circuit card into ACT mode referring to How to Control Switching Block
in Chapter 2 .
(c) Check to see if a station-to-station connection can be set up and identify a circuit card responsible for
the fault.
(d) Perform the above check by extracting each MUX circuit card individually.