NEC NDA-24300 manual Unit Fault When Dial Tone DT Cannot Be Heard, For Dual Configuration

FAULT REPAIR PROCEDURES

4.3 Unit Fault - When Dial Tone (DT) Cannot Be Heard

Faulty Situation:

•Dial Tone (DT) cannot be heard except within a unit.

•[4-T] Both MUX Failure / [4-S] MUX Ready Failure

•[23-Y] MUX Clock Failure

ATTENTION

Contents Static Sensitive

Handling Precautions Required

Note: For dual system configuration, if a system message indicates that both systems are faulty, first repair the fault in the indicated system and then proceed to repair the PIM in the other system.

(1)For Dual Configuration

START

A

Check to see if the MUX (PH-PC36) circuit card is making poor contact.

Check by replacing the MUX circuit card with a spare.

B

Set the MUX circuit card into STBY mode by flipping the MBR key on the active GT (PH- GT09) card. Refer to Section 12.1.6, Manual System Changeover of Speech Path System, in Chapter 6.

Set the MB switch of the MUX circuit card UP.

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.

Set the MB switch of the MUX circuit card UP and insert the circuit card into its mounting slot.

Set the MB switch of the MUX circuit card DOWN.

Check to see if a station-to-station connection can be set up within the faulty unit.

Place the MUX circuit card into STBY mode by flipping the MBR key on the active GT (PH- GT09) card. Refer to Section 12.1.6, Manual System Changeover of Speech Path System, in Chapter 6.

Replace the MUX circuit card. Refer to Section 3.3.2, MUX Card Replacement Procedure, in Chapter 4.

CHAPTER 5 NDA-24300

Page 340

Issue 1