No Acoustic Line Monitor - Oki OKIFAX4550 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
Start
MONITOR VOLUME
(Function program No. 06)
has been set to
LOW or HIGH?
Yes
MONITOR CONTROL
(Technical function No. 02)
has been set to OFF?
No (ON)
Connect oscilloscope probe
across CN9-1 (SP) and
CN9-2 (AG).
The signal appears?
No
A message can be
received normally?
Yes
Replace MCNT Board.
Signal route:
<46F>
CN10-A2→IC12-1 (RM)→
TR501→IC11-12~15→
IC11-3→IC5-5
<R46>
CN10-A2→IC10-1 (RM)→
TR1→IC8-12~15→
IC8-3→IC11-5
41309401TH Rev.4
No
Set MONITOR VOLUME
to LOW or HIGH.
Yes (OFF)
Set it to ON.
Yes
Replace the speaker.
No
Go to 7.9.
(Reception problem)
238 /