Panasonic KX-TC1025RUB Service Manual ▷ View online
28.3. Transmitter Signal Circuit
Circuit Operation:
Input signal from MIC passes through the filters arranged by C202, VR201, R201 and C203, R203 and it is input to the Pin
Input signal from MIC passes through the filters arranged by C202, VR201, R201 and C203, R203 and it is input to the Pin
of
IC101.
Inside it, the signal passes through the MIC AMP and Compressor circuits and SPLATTER FILTER is output to Pin
Inside it, the signal passes through the MIC AMP and Compressor circuits and SPLATTER FILTER is output to Pin
.
It flows through R204, C221, R221, then is input to modulator circuit.
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KX-TC1025RUB
28.4. Receiver Data Circuit
Circuit Operation:
Only received data pass through the low pass filter conformed by R216 and C129 to be input to pin
Only received data pass through the low pass filter conformed by R216 and C129 to be input to pin
of IC101, where its wave
form is adjusted.
The resulting signal is output from Pin
The resulting signal is output from Pin
and sent to CPU directly.
28.5. Battery Low Detector Circuit
Circuit Operation:
When the battery voltage goes down less than 3.60 V. this level is detected by the input of IC101, so its output send to Pin
When the battery voltage goes down less than 3.60 V. this level is detected by the input of IC101, so its output send to Pin
of
IC901.
The CPU detects this level by its Pin
The CPU detects this level by its Pin
and battery low indicator lights starts flashing.
The IC101 check the level of the battery, if this level is less than 3.4 V, the output of Pin
of IC101, then CPU stops working to
keep memory.
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KX-TC1025RUB
Reset circuit
There are two ways to reset CPU.
There are two ways to reset CPU.
29 NORMAL CIRCUIT OPERATION (HANDSET)
29.1. CPU Operation
29.2. Reset Circuit Power ON/OFF Circuit
1. When the battery is connected, there is an impulse through C906 then Q910 generates an reset signal which is received in Pin
of CPU.
2. When the handset is charged, the impulse is sent through C905, Q910 generates the reset signal and it is sent to Pin
of
CPU.
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KX-TC1025RUB
30 TROUBLESHOOTING GUIDE
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KX-TC1025RUB
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