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KX-DT543/KX-DT543-B/KX-DT546/KX-DT546-B
8.8.
Speaker-Phone/Ringer Does Not Work
8.8.1.
Receive / Ringer
8.8.2.
Send
Check the soldering.
Resolder or replace parts as needed.
Related parts: IC410,C500,C501,R501,R502,
C502,C506,C504
NO
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
Related parts: Speaker,Speaker-cable
NO
YES
Can you hear dial tone from Speaker-phone
speaker?
END
Check the soldering.
Resolder or replace parts as needed.
Related parts: [Main PCB] R535,R533,R532,
C540,C541,R530,R531,C530,
IC410
[mini PCB for microphone]
R1,R2, MIC1
NO
END
Related parts: C540,R532,R565,R534,C569
NO
YES
Confirm the voltage between TP:MIP and
TP:UART_GND.
Is it about 1.9V?
Related parts: IC410,C442,R238,C443
NO
YES
Confirm the voltage between either end of
C443 (MICBIAS).
Is it about 2.5V?
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?