No Acoustic Line Monitor - Oki OKIFAX 5750 Maintenance Manual

7.16 No Acoustic Line Monitor

There are two source routes of acoustic line monitor:
(a) General communication signal
(b) DP pulse signal
(Machine settings No. 11)
HIGH-MID/MID/LOW/OFF
(Technical setup No. 02)
Connect oscilloscope probe
across CN10-1 (SP) and
Receive signal appears
acrossCN11-A22 (R) of
Receive signal appears
acrossCN201-5 (RM) of
C34 or H34 Modem board?
Replace MCNT (R76) Board.
41285901TH Rev.3
Start
MONITOR VOLUME
has been set to HIGH/
Yes
MONITOR CONTROL
has been set to OFF?
No (ON)
CN10-2 (AG).
Yes
The signal appears?
No
A message can be
received normally?
Yes
MCNT (R76) board?
Yes
Yes
Signal route:
CN11-B23→TRI5-2, 1→
IC21-12, 3→IC20-3, 5→CN10-1
No
Set MONITOR VOLUME to
HIGH/HIGH-MID/MID/LOW/OFF
Yes (OFF)
Set it to ON.
Replace the speaker.
No
Go to 7.9.
(Reception problem)
No
Replace MCNT (R76) board.
Signal route:
CN12-A6, B6→CN11-A22
No
Replace C34 or H34
Modem board
Signal route:
CN201-8→IC204-2, 1→CN201-5
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