Read Panasonic KX-TG8421RUB / KX-TG8421RUN / KX-TG8421RUT / KX-TG8421RUW / KX-TG8422RUB / KX-TG8422RUN / KX-TGA840RUB / KX-TGA840RUN / KX-TGA840RUT / KX-TGA840RUW Service Manual online
KX-TG8421RUN
KX-TG8421RUT
KX-TG8421RUW
KX-TG8422RUB
KX-TG8422RUN
KX-TGA840RUB
KX-TGA840RUN
KX-TGA840RUT
KX-TGA840RUW
N:Platinum Silver Version
T:Titanium Black Version
W:White Version
(for Russia)
2.2. About Lead Free Solder (Pbf: Pb free)--------------- 4
2.3. Discarding of P.C. Board--------------------------------- 5
4 Technical Descriptions ----------------------------------------- 7
4.2. Circuit Operation (Base Unit) --------------------------- 8
4.3. Block Diagram (Handset)-------------------------------11
4.4. Circuit Operation (Handset)----------------------------12
4.5. Circuit Operation (Charger Unit) ----------------------13
4.6. Signal Route -----------------------------------------------14
6.2. Battery-------------------------------------------------------17
7.2. Registering a Handset to a Base Unit---------------22
7.3. Copying Phonebook Entries ---------------------------23
7.4. Dialling Mode ----------------------------------------------23
7.5. Error Messages -------------------------------------------23
7.6. Troubleshooting-------------------------------------------24
7.7. For Service Hint-------------------------------------------29
8.2. Copying Phonebook Items when Repairing -------34
8.3. How to Clear User Setting------------------------------36
9.2. Troubleshooting by Symptom (Base Unit and
10.2. How to Replace the Handset LCD -------------------61
11.2. The Setting Method of JIG (Base Unit) -------------62
11.3. Adjustment Standard (Base Unit)---------------------64
11.4. Adjustment Standard (Charger Unit)-----------------65
11.5. The Setting Method of JIG (Handset) ---------------66
11.6. Adjustment Standard (Handset) ----------------------68
11.7. Things to Do after Replacing IC or X'tal ------------69
11.8. RF Specification-------------------------------------------71
11.9. How to Check the Handset Speaker or
12.2. CPU Data (Handset)-------------------------------------75
12.3. How to Replace the Flat Package IC----------------77
12.4. How to Replace the LLP (Leadless Leadframe
13.2. Schematic Diagram (Base Unit)---------------------- 84
13.3. Schematic Diagram (Base Unit_Operation) ------- 86
13.4. Schematic Diagram (Handset)------------------------ 88
13.5. Schematic Diagram (Charger Unit)------------------ 90
14.2. Circuit Board (Base Unit_Operation)---------------- 93
14.3. Circuit Board (Handset) -------------------------------- 94
14.4. Circuit Board (Charger Unit)--------------------------- 96
15.2. Cabinet and Electrical Parts (Handset)------------- 98
15.3. Cabinet and Electrical Parts (Charger Unit) ------- 99
15.4. Accessories and Packing Materials --------------- 100
15.5. Replacement Part List -------------------------------- 103
2. If a lead wire assembly is supplied as a repair part, the lead wire assembly shall be replaced.
3. FASTON terminals shall be plugged straight in and unplugged straight out.
2. Ground the soldering irons.
3. Use a conductive mat on worktable.
4. Do not grasp IC or LSI pins with bare fingers.
2. Replace only with the same or equivalent type recommended by the manufacturer.
3. Dispose of used batteries according to the manufacture’s Instructions.
tains lead.
We will use PbF solder when discussing the lead free solder used in our manufacturing process which is made from Tin (Sn),
Silver (Ag), and Copper (Cu).
This model, and others like it, manufactured using lead free solder will have PbF stamped on the PCB. For service and repair
work we suggest using the same type of solder.