DOWNLOAD Panasonic KX-TG6421RUC / KX-TG6421RUM / KX-TG6421RUT / KX-TG6422RU1 / KX-TGA641RUC / KX-TGA641RUM / KX-TGA641RUT Service Manual ↓ Size: 2.64 MB | Pages: 107 in PDF or view online for FREE

Model
KX-TG6421RUC KX-TG6421RUM KX-TG6421RUT KX-TG6422RU1 KX-TGA641RUC KX-TGA641RUM KX-TGA641RUT
Pages
107
Size
2.64 MB
Type
PDF
Document
Service Manual
Brand
Device
Telephone / DIGITAL CORDLESS ANSWERING SYSTEM
File
kx-tg6421ruc-kx-tg6421rum-kx-tg6421rut-kx-tg6422ru.pdf
Date

Panasonic KX-TG6421RUC / KX-TG6421RUM / KX-TG6421RUT / KX-TG6422RU1 / KX-TGA641RUC / KX-TGA641RUM / KX-TGA641RUT Service Manual ▷ View online

46
KX-TG6421RUC/KX-TG6421RUM/KX-TG6421RUT/KX-TG6422RU1/KX-TGA641RUC/KX-TGA641RUM/KX-TGA641RUT
9.1.8.
Bell Reception
9.1.8.1.
Base Unit
9.1.8.2.
Handset
Cross Reference:
Telephone Line Interface (P.10)
Check Link (P.38)
How to Check the Handset Speaker or Receiver (P.70)
9.1.9.
Check TAM Operation
Cross Reference:
Power Supply Circuit (P.9)
Note:
(*1) When replacing FLASH MEMORY (IC421), TAM data need to be written to it. Refer to Base Unit of Things to Do after
Replacing IC or X'tal
 (P.67)
47
KX-TG6421RUC/KX-TG6421RUM/KX-TG6421RUT/KX-TG6422RU1/KX-TGA641RUC/KX-TGA641RUM/KX-TGA641RUT
9.2.
Troubleshooting by Symptom (Base Unit and Charger Unit)
If your unit has below symptoms, follow the instructions in remedy column. Remedies depend on whether you have DECT tester
(*1) or not. 
Note:
(*1) A general repair is possible even if you don’t have the DECT tester because it is for confirming the levels, such as Acoustic
level in detail.
(*2) Refer to Check Point (Base Unit) (P.47)
9.2.1.
Check Point (Base Unit)
Please follow the items below when BBIC or EEPROM or FLASH is replaced.
Note:
After the measuring, suck up the solder of TP.
*: The Setting Method of JIG (Base Unit) (P.60) is required beforehand.
The connections of simulator equipments are as shown in Adjustment Standard (Base Unit) (P.62).
Items
Check 
Point
Procedure
Check or 
Replace Parts
(A) 3.0 V Supply Confirma-
tion
VDD3
1. Confirm that the voltage between test point VDD3 and GND is 3.0 V ± 0.2 V.
IC1, C31, C32, 
R38, R39, C36, 
F1, C37, D1
(B) 1.8 V Supply Confirma-
tion
VDD1
1. Confirm that the voltage between test point VDD1 and GND is 1.8 V ± 0.02 V.
2. Execute the command “VDD”, then check the current value.
3. Adjust the 1.8V voltage of VDD1 executing command “VDD XX“(XX is the
value).
Q8, C75, C614, 
C61, IC7
(C) Charge Pump
2.5V Supply Confirma-
tion
VDD5
1. Confirm that the voltage between test point VDD5 and GND is 2.5 V  -0.1/+0.3
V. 
IC7,C625,C631
(D) Charge Pump
3.0V Supply Confirma-
tion
VDD4
1. Confirm that the voltage between test point VDD4 and GND is 3.0 V ± 0.2 V.  IC7,C616,C630
(E)*
BBIC Confirmation
-
1. BBIC Confirmation (Execute the command “getchk”).
2. Confirm the returned checksum value.
Connection of checksum value and program number is shown below.
IC7, X1, R77, 
RA80
(F)* EEPROM Confirmation
-
1. EEP-ROM Confirmation (Execute the command "sendchar EPV").
2. Confirm the returned Value. (Value for reference is written at "EEPROM C/
SUM" in Software_Version_Table.xls).
IC7, RA402, 
C51, R657, 
IC401
(G)* BBIC Clock Adjustment
CLK
1. Input Command “ sendchar WWD ff 48 IC 8006”
2. Confirm that the voltage between testpoint VDD4 and GND is less than 1.0 V.
3. Input Command “ sendchar sfr”, then you can confirm the current value.
4. Check X’tal Frequency. (10.368 MHz ± 100 Hz).
5. If the frequency is not 10.368MHz ± 100Hz, adjust the frequency of CLK exe-
cuting the command “sendchar sfr xx xx (where xx is the value)” so that the
reading of the frequency counter is 10.368000 MHz ± 5 Hz.
X1, IC7, R430,  
C305
48
KX-TG6421RUC/KX-TG6421RUM/KX-TG6421RUT/KX-TG6422RU1/KX-TGA641RUC/KX-TGA641RUM/KX-TGA641RUT
(H)* Hookswitch Check with 
DC Characteristics
-
1. Connect Telephone Socket to Tel-simulator which is connected with 600 
Ω.
2. Set line voltage to 48 V and line current to 40mA at off-hook condition of nor-
mal telephone.
3. Execute the command “hookoff”
4. Confirm that the line current is 40 mA ± 5 mA.
5. Execute the command “hookon”.
6. Confirm that the line current is less than + 0.8 mA.
L1, L2, Q3, R14, 
R15, Q4, R16, 
R17, D3, 
R18~R24, 
C15~C17, D21, 
Q5, R27, IC7
(I) DTMF Generator Check
-
1. Connect Telephone Socket to DTMF tester. (Load=600 
Ω)
2. Link Handset and push dial key.
3. Confirm DTMF character.
4. Confirm that the high Group is -6.0 dBm ~ -10.0 dBm.
5. Confirm that the low Group is -8.5 dBm ~ -12.5 dBm.
IC7, R116, 
C141, R29, C22, 
C23, Q5, D21
(J)* Transmitted Power Con-
firmation
-
ANTI_TP
Remove the Antenna before starting step from 1 to 7.
1. Configure the DECT tester (CMD60) as follows;
<Setting>
• Test mode: FP
• Traffic Carrier: 5
• Traffic Slot: 4
• Mode: Loopback
• PMID: 00000
• RF LEVEL = -70 dBm.
2. Execute the command ”sendchar TST”.
3. Execute the command “sendchar dmv 2 2”.
4. Check that “Signalling Status” has been set to “Locked”, then press “ACCEPT
RFPI”.
5. Initiate connection from Dect tester (“set up connect”)
6. Execute the command “ANT1”.
7. Confirm that the NTP value at ANT is 19.0 dBm ~ 25.0 dBm.
IC7, 
C802~C806, 
C808~C814, 
C820, C819,  
C822, C823, 
C825, C827, 
C826, C834, 
C851, C853, 
C859~C861, 
DA801, DA802, 
IC801, 
L801~L803, 
C855~C858, 
R801~R807, 
R106, R109, 
Q9, C617 
(K)* Modulation Check and 
Adjustment
-
ANTI_TP
Follow steps 1 to 6 of (J).
7.Confirm that the B-Field Modulation is -370 ± 30/ +370± 30 kHz/div & Modu-
lated width   690 kHz using data type Fig31.
8.Adjust the B-Field Modulation if required. (Execute the command “readmod”
and “wrtmod xx”, where xx is the value.)
IC7, 
C802~C806, 
C808~C814, 
C820, C819,  
C822, C823, 
C825, C827, 
C826, C834, 
C851, C853, 
C859~C861, 
DA801, DA802, 
IC801, 
L801~L803, 
C855~C858, 
R801~R807, 
R106, R109, 
Q9, C617 
(L)* Frequency Offset Check
-
ANTI_TP
Follow steps 1 to 6 of (J).
7.Confirm that the frequency offset is < ± 50 kHz.
IC7, 
C802~C806, 
C808~C814, 
C820, C819,  
C822, C823, 
C825, C827, 
C826, C834, 
C851, C853, 
C859~C861, 
DA801, DA802, 
IC801, 
L801~L803, 
C855~C858, 
R801~R807, 
R106, R109, 
Q9, C617 
Items
Check 
Point
Procedure
Check or 
Replace Parts
49
KX-TG6421RUC/KX-TG6421RUM/KX-TG6421RUT/KX-TG6422RU1/KX-TGA641RUC/KX-TGA641RUM/KX-TGA641RUT
(M)* Frequency Drift Confir-
mation
-
ANTI_TP
Follow steps 1 to 6 of (J).
7.Confirm that the frequency drift is < ± 35 kHz/ms.
IC7, 
C802~C806, 
C808~C814, 
C820, C819,  
C822, C823, 
C825, C827, 
C826, C834, 
C851, C853, 
C859~C861, 
DA801, DA802, 
IC801, 
L801~L803, 
C855~C858, 
R801~R807, 
R106, R109, 
Q9, C617 
(N)*
Sensitivity Receiver 
Confirmation
-
ANTI_TP
Follow steps 1 to 6 of (J).
7.Set DECT tester power to -90 dBm.
8.Confirm that the BER is < 1000 ppm.
IC7, 
C802~C806, 
C808~C814, 
C820, C819,  
C822, C823, 
C825, C827, 
C826, C834, 
C851, C853, 
C859~C861, 
DA801, DA802, 
IC801, 
L801~L803, 
C855~C858, 
R801~R807, 
R106, R109, 
Q9, C617 
(O)*
Timing Confirmation
-
ANTI_TP
Follow steps 1 to 6 of (J).
7.Confirm that the Timing accuracy is
• ± 5.0 ppm (When adjust the frequency of CLK in item (G)).
• ± 15 ppm (When do not adjust the frequency of CLK in item (A)).
IC7, 
C802~C806, 
C808~C814, 
C820, C819,  
C822, C823, 
C825, C827, 
C826, C834, 
C851, C853, 
C859~C861, 
DA801, DA802, 
IC801, 
L801~L803, 
C855~C858, 
R801~R807, 
R106, R109, 
Q9, C617 
(P)* Power RAMP Confirma-
tion
-
Follow steps 1 to 6 of (J).
7.Confirm that Power RAMP is matching.
IC7, 
C802~C806, 
C808~C814, 
C820, C819,  
C822, C823, 
C825, C827, 
C826, C834, 
C851, C853, 
C859~C861, 
DA801, DA802, 
IC801, 
L801~L803, 
C855~C858, 
R801~R807, 
R106, R109, 
Q9, C617 
Items
Check 
Point
Procedure
Check or 
Replace Parts
Page of 107
Display

Click on the first or last page to see other KX-TG6421RUC / KX-TG6421RUM / KX-TG6421RUT / KX-TG6422RU1 / KX-TGA641RUC / KX-TGA641RUM / KX-TGA641RUT service manuals if exist.