Its (Integrated Telephone System) And Monitor - Panasonic KX-FT21RS Serivce Manual

KX-FT21RS
6.9. ITS (Integrated telephone System) and MONITOR SECTION
6.9.1. GENERAL
During the monitor operation, the speaker output passes through the power amplifier (IC102) [Analog board].
The DTMF signal is output from the modem (IC1: digital board). The alarm tone, the key tone, bell tone, and beep are output from
gate array IC1 (digital board). During a pulse dial operation, the monitor tone is output from gate array IC1.
6.9.2. MONITOR CIRCUIT
1. Function
This is the function when you are not holding the handset and can hear the caller´s voice from the line.
2. Circuit Operation
(Monitor Signal Path)
6.9.3. HANDSET CIRCUIT
1. Transmission signal
2. Reception Signal
TEL LINE D1
IC103 (11) IC103 (10)
R13 IC1 (62)
CN202 (10) J402
6.9.4. MONITOR CIRCUIT
1. DTMF Monitor
(Monitor)
(Handset)
[IC1 IC5 IC5 (3)
R13 IC1 (62)
CN202 (10) J402
2. Alarm/Beep/Key tone/Bell
[IC1 (59) R28
C67 CN10 (9)]
3. Dummy Ring Back Tone
Same with the modem signal transmission.
Q4 (E) Q4 (C) C8 T101
CN102 (10) [CN9 (10)
IC1 (63) C62 IC8 (5)
C234 R209 Q201 (B)
C48 R37 R38
IC1 (63) C62 IC8 (5)
C234 R209 Q201 (B)
C45 R35 IC8 (2) IC8 (1)
CN202 (9) R122 IC102 (4)
R104 C107 R112
IC6 (3) IC6 (4)
IC8 (7) R60 C63 IC6 (8)
Q201 (E) C205 L202
IC9 (2) IC9 (1) C54
IC8 (7) R60 C63 IC6 (8)
Q201 (E) C205 L202
C27 R13 IC1 (62)
IC102 (5) SPEAKER
132
IC101 (6) IC101 (7)
C52 R42 IC8 (2) IC8 (1)
IC6 (9) C65 CN10 (10)]
HANDSET SPEAKER
R44 IC8 (2) IC8 (1)
IC6 (9) C65 CN10 (10)]
HANDSET SPEAKER
IC1 (63) C62 IC8 (5)
C127
C27
C27
IC8 (7)