Panasonic KX-TG6421RUC / KX-TG6421RUM / KX-TG6421RUT / KX-TG6422RU1 / KX-TGA641RUC / KX-TGA641RUM / KX-TGA641RUT Service Manual ▷ View online
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KX-TG6421RUC/KX-TG6421RUM/KX-TG6421RUT/KX-TG6422RU1/KX-TGA641RUC/KX-TGA641RUM/KX-TGA641RUT
(K)* Frequency Offset Confir-
mation
-
Follow steps 1 to 3 of (I).
4.Confirm that the frequency Offset is < ± 50 kHz.
IC1,
C802~C806,
C808~C814,
C819~C820,
C808~C814,
C819~C820,
C822,
C825~C827,
C834,
C859~C864,
L801~L804,
DA801,
R801~R808
(L)* Frequency Drift Confir-
mation
-
Follow steps 1 to 3 of (I).
4.Confirm that the frequency Drift is < ± 35 kHz/ms.
IC1,
C802~C806,
C808~C814,
C819~C820,
C808~C814,
C819~C820,
C822,
C825~C827,
C834,
C859~C864,
L801~L804,
DA801,
R801~R808
(M)*
Sensitivity Receiver
Confirmation
-
Follow steps 1 to 3 of (I).
4.Set DECT tester power to -88 dBm.
5.Confirm that the BER is < 1000 ppm.
5.Confirm that the BER is < 1000 ppm.
IC1,
C802~C806,
C808~C814,
C819~C820,
C808~C814,
C819~C820,
C822,
C825~C827,
C834,
C859~C864,
L801~L804,
DA801,
R801~R808
(N)* Power RAMP Confirma-
tion
-
Follow steps 1 to 3 of (I).
4.Confirm that Power RAMP is matching.
IC1,
C802~C806,
C808~C814,
C819~C820,
C808~C814,
C819~C820,
C822,
C825~C827,
C834,
C859~C864,
L801~L804,
DA801,
R801~R808
(O) Audio Check and Confir-
mation
-
1. Link to BASE which is connected to Line Simulator.
2. Set line voltage to 48 V and line current to 40 mA.
3. Input -45 dBm/1KHz to MIC and measure Line output level.
4. Confirm that the level is -10 dBm ± 2 dBm and that the distortion level is < 5%
2. Set line voltage to 48 V and line current to 40 mA.
3. Input -45 dBm/1KHz to MIC and measure Line output level.
4. Confirm that the level is -10 dBm ± 2 dBm and that the distortion level is < 5%
at TEL Line (600
Ω Load).
5. Input -20 dBm/1KHz to Line I/F and measure Receiving level at REV+ and
REV-.
6. Confirm that the level is -21 dBm ± 2 dBm and that the distortion level is < 5%
at Receiver. (vol = 2)
IC1, C12, D19,
D20, C96,
C97, R215,
R27, RA4,
C11, C13,
R28, D3, D4,
MIC, L9, RA2,
R73, R74
(P) SP phone Audio Check
and Confirmation
-
1. Link to Base which is connected to Line Simulator.
2. Set line voltage to 48 V and line current to 40 mA.
3. Set the handset off-hook using SP-Phone key.
4. Input -25 dBm/1KHz to Line I/F and measure Receiving level at SP+ and SP-.
5. Confirm that the level is -15 dBm ± 2 dBm and that the distortion level is < 5%.
2. Set line voltage to 48 V and line current to 40 mA.
3. Set the handset off-hook using SP-Phone key.
4. Input -25 dBm/1KHz to Line I/F and measure Receiving level at SP+ and SP-.
5. Confirm that the level is -15 dBm ± 2 dBm and that the distortion level is < 5%.
(vol = 3)
IC1, C12, C73,
D13, D14,
R152, R73,
R74, RA2,
MIC, C11,
C13, RA4,
R27, R28,
R208, R209,
C96, C97,
R215, C72
(Q) Charge Pump 3.0V Sup-
ply Confirmation
CP3.0V
1. Confirm that the voltage between testpoint CP3.0V and GND is 3.0V -0.1/
+0.3V.
C52, C53, C49
(R) Charge Pump 4.0V Sup-
ply Confirmation
CP4.0V
1. Confirm that the voltage between testpoint CP4.0V and GND is 4.0V -0.2V.
C50, C51
Items
Check
Point
Procedure
Check or
Replace Parts
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KX-TG6421RUC/KX-TG6421RUM/KX-TG6421RUT/KX-TG6422RU1/KX-TGA641RUC/KX-TGA641RUM/KX-TGA641RUT
9.3.2.
Troubleshooting for Speakerphone
When the customer’s telephone line corresponds to the following conditions, and the transmission signal of SP-Phone is inter-
rupted, performing the next set up to a cordless handset will improve it to some extent.
Conditions
rupted, performing the next set up to a cordless handset will improve it to some extent.
Conditions
1. When customer’s line has less line loss.
ex.) The customer is using optical fiber, ISDN terminal adaptor, or PBX.
In this case, receiving signal is strong and it may affect transmission signal.
In this case, receiving signal is strong and it may affect transmission signal.
2. When the other party is talking from noisy place.
ex.) The other party is using cellular phone. The background noise is very loud.
In this case, the noise from the other party (i.e. surrounding noise) may affect transmission signal.
In this case, the noise from the other party (i.e. surrounding noise) may affect transmission signal.
Setting Method
• Change the handset address of EEPROM (0129) from 00 to 01 by Engineering Mode.
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KX-TG6421RUC/KX-TG6421RUM/KX-TG6421RUT/KX-TG6422RU1/KX-TGA641RUC/KX-TGA641RUM/KX-TGA641RUT
10 Disassembly and Assembly Instructions
10.1. Disassembly Instructions
10.1.1. Base Unit
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KX-TG6421RUC/KX-TG6421RUM/KX-TG6421RUT/KX-TG6422RU1/KX-TGA641RUC/KX-TGA641RUM/KX-TGA641RUT
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