3.6 3
Incoming Call:
I
Check connection to exchange line.
2
Check that the LED flashes with incoming ring on the ELNB board for the incoming line. If
the LED does flash refer to maintenance flow charts for further fault diagnosis.
3
Check that the system is dialling out, if not check that it is set up
Decadic Dialling:
ELNB DCB-A daughter board has key in location 12.
ETSB B installed.
ETSB C installed if more than 16 exchange lines, are used.
System programmed for decadic dialling.
Voice Frequency Dialling:
ELNB DCB-A daughter board has key in location 13.
ETSB A installed.
System programmed for voice frequency dialling.
3.6.4
1.
2.
3.
4.
3.6.5
1.
2.
3.6.6
1.
2.
3.
3.6.7
1.
2.
3.
Incoming Call:
Check the system programming data for exchange line audible signalling.
Check the wiring from the main equipment to stations as in section 3.6.1. (Check that the
stations are connected to the correct SDF terminals).
Check that exchange lines are connected in the correct sequence.
If there are no signalling tones at all, change the ETSB-A/B board.
Incoming Call:
Check that system programming assigns exchange line audible signalling to station A and
that Off Hook signalling is assigned.
Check that the speaker is connected in station A (to
and
If it is, replace station A.
Answering:
Check wiring from main equipment to station B (check voltages as in
Check fuse on ESTB board for station B.
Change station B.
Answering:
Check A pair wiring (and DC voltages) to station A and station B.
Check stations A and B for sidetone, if there is no sidetone, check transmitter and receiver
and station wiring as
Transmitter
RD, BK
Receiver
Standard Station (figure
Straps
RR to
Powerfail Station (figure
Wires from Dial Board
WIRE
TERMINALS
BN
GN
C
RB
BL
OR
RR
BK
BK
B
not connected
and insulated
Change station B.
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ISSUE 1