Speaker-Phone/Ringer Does Not Work; Receive / Ringer; Send - Panasonic KX-DT543-B Service Manual

8.8.

Speaker-Phone/Ringer Does Not Work

8.8.1.

Receive / Ringer

Confirm the waveform of dial tone between TP:SPP
and TP:SPN, when you press the speaker button.
(Speaker-phone mode).
Can you see the waveform of dial tone?
YES
Can you hear dial tone from Speaker-phone
speaker?
YES
END
8.8.2.

Send

Confirm the voltage between either end of
C443 (MICBIAS).
Is it about 2.5V?
YES
Confirm the voltage between TP:MIP and
TP:UART_GND.
Is it about 1.9V?
YES
Confirm the waveform of sending sound from
Speaker-phone microphone between TP:MIP and
TP:MIN during a call.
Can you see the waveform of sending sound?
YES
END
Check the soldering.
Resolder or replace parts as needed.
NO
Related parts: IC410,C500,C501,R501,R502,
NO
Related parts: Speaker,Speaker-cable
Check the soldering.
Resolder or replace parts as needed.
NO
Related parts: IC410,C442,R238,C443
NO
Related parts: C540,R532,R565,R534,C569
Related parts: [Main PCB] R535,R533,R532,
NO
33
KX-DT543/KX-DT543-B/KX-DT546/KX-DT546-B
C502,C506,C504
C540,C541,R530,R531,C530,
IC410
[mini PCB for microphone]
R1,R2, MIC1