Panasonic KX-FLM551, Service Manual

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the FAX mode by using a DTMF signal.
2. Signal Path
TEL LINE T203 R269 C285 IC207(6-7) C266 C227
R223 IC201(20 31) CN202 (4) CN616 (25) C723 R707
IC609 (13 22) IC604 (P1)
7.3.5.4.7. TAM INTERFACE CIRCUIT
This circuit is to switch between FAX receiving and the external TAM’s message recording
automatically. This circuit consists of an EXT. TAM OFF-HOOK detect circuit, line transformer,
multiplexer, amplifier.
For details, please refer
TAM INTERFACE SECTION ().
7.3.5.5. ITS (Integrated telephone System) and MONITOR SECTION
7.3.5.5.1. GENERAL
The general ITS operation is performed by the special IC201 which has a handset circuit. The
alarm tone, the key tone, and the beep are output from the ASIC IC604 (digital board).
7.3.5.5.2. TELEPHONE MONITOR
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
(Telephone Monitor Signal Path)
Signals received from the telephone line are output through at the
speaker via the following path.
3. Signal Path
Refer to CHECK SHEET .
7.3.5.5.3. HANDSET CIRCUIT
1. Function
This circuit controls the conversation over the handset, i.e. the
transmitted and received voices to and from the handset.
2. Signal Path (Transmission signal)
Refer to CHECK SHEET .
3. Signal path (Reception signal)
Refer to CHECK SHEET .
7.3.5.5.4. MONITOR CIRCUIT
1. Function
This circuit monitors various tones, such as (1) DTMF tone, (2)
Alarm/Beep/Key tone/Bell (3) Dummy ring back tone.
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