Panasonic KX-MB1520FX7, Service Manual

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KX-MB1520FX7/KX-MB1520FX8/KX-MB1520FXW/KX-MB1530FX7/KX-MB1530FXW
6.5. Speaker Phone Section
6.5.1. General
The general speaker phone operation is performed by IC203 which has a speaker phone circuit. The alarm tone, the key tone,
and the beep are output from Soc IC300.
6.5.1.1. Speaker Phone
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
(Signal Path)
Signals received from the telephone line are output through at the speaker via the following path.
Voice sended from MIC to telephone line.
3. Signal Path
Refer to Check Sheet for Signal Route of Speaker RX and Mic Tx (P.170).
6.5.1.2. Monitor Circuit
1. Function
This circuit monitors various tones, such as (1) DTMF tone, (2) Alarm/Beep/Key tone/Bell.
2. Signal Path
a. DTMF MONITOR
(Speaker Operation)
Refer to
Check Sheet for Signal Route of DTMF Monitor (Speaker) (P.170).
b. ALARM/BEEP/KEY TONE/BELL
Refer to Check Sheet for Signal Route of Ringing/Alarm/Beep/Key tone (P.170).
6.5.1.3. TAM Interface Section
1. Function
When TAM is connected to this unit, the unit receives documents for FAX calls or the external TAM records a voice message
automatically.
2. Circuit Operation
The TAM INTERFACE circuit consists of Soc(IC300) to detect the other party CNG signal, and RLY100 to separate EXT.TAM.
a. CNG signal detection circuit
The CNG signal from the other party’s FAX is detected in Soc IC300
(Signal path)
Refer to
Check Sheet for Signal Route of CNG/DTMF detection (P.170).
b. Remote receiving
This is the parallel-connected DTMF signal for the TEL or EXT.TEL mode between T and R. When the other party is a
FAX, the unit switches to FAX receiving.
(Signal Path)
Refer to
Check Sheet for Signal Route of DTMF detection (ON-Hook) (P.170).