KX-TG7321CAC, KX-TGA731RUC - Panasonic Telephone Service Manual (repair manual). Page 3

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1 Safety Precautions----------------------------------------------- 4

1.1. For Service Technicians --------------------------------- 4

2 Warning -------------------------------------------------------------- 4

2.1. Battery Caution--------------------------------------------- 4
2.2. About Lead Free Solder (Pbf: Pb free)--------------- 4
2.3. Discarding of P.C. Board--------------------------------- 5

3 Specifications ----------------------------------------------------- 6
4 Technical Descriptions ----------------------------------------- 7

4.1. Block Diagram (Base Unit) ------------------------------ 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

5 Location of Controls and Components ------------------16

5.1. Controls -----------------------------------------------------16

6 Installation Instructions ---------------------------------------17

6.1. Connections------------------------------------------------17
6.2. Battery-------------------------------------------------------18

7 Operating Instructions-----------------------------------------19

7.1. Programmable Settings ---------------------------------19
7.2. Registering a Handset to the Base Unit ------------20
7.3. Copying Phonebook Entries ---------------------------21
7.4. Dialling mode ----------------------------------------------21
7.5. Error Messages -------------------------------------------21
7.6. Troubleshooting-------------------------------------------22
7.7. For Service Hint-------------------------------------------25

8 Service Mode -----------------------------------------------------26

8.1. Engineering Mode ----------------------------------------26
8.2. Copying Phonebook Items when Repairing -------30
8.3. How to Clear User Setting------------------------------32

9 Troubleshooting Guide ----------------------------------------33

9.1. Troubleshooting Flowchart -----------------------------33
9.2. Troubleshooting by Symptom (Base Unit and

Charger Unit) ----------------------------------------------45

9.3. Troubleshooting by Symptom (Handset) -----------49
9.4. How to Replace the Flat Package IC----------------53
9.5. How to Replace the LLP (Leadless Leadframe

Package) IC------------------------------------------------55

10 Disassembly and Assembly Instructions ---------------57

10.1. Disassembly Instructions -------------------------------57
10.2. How to Replace the Handset LCD -------------------61

11 Measurements and Adjustments---------------------------62

11.1. The Setting Method of JIG (Base Unit) -------------62
11.2. Adjustment Standard (Base Unit)---------------------64
11.3. Adjustment Standard (Charger Unit)-----------------65
11.4. The Setting Method of JIG (Handset) ---------------66
11.5. Adjustment Standard (Handset) ----------------------68
11.6. Things to Do after Replacing IC or X'tal ------------69
11.7. RF Specification-------------------------------------------71
11.8. How to Check the Handset Speaker or

Receiver ----------------------------------------------------72

11.9. Frequency Table (MHz) ---------------------------------72

12 Schematic Diagram ---------------------------------------------73

12.1. For Schematic Diagram---------------------------------73
12.2. Schematic Diagram (Base Unit) ----------------------74
12.3. Schematic Diagram (Base Unit_Operation) -------76
12.4. Schematic Diagram (Handset) ------------------------78

12.5. Schematic Diagram (Charger Unit)------------------ 80

13 Printed Circuit Board ------------------------------------------ 81

13.1. Circuit Board (Base Unit_MAIN) --------------------- 81
13.2. Circuit Board (Base Unit_Operation)---------------- 83
13.3. Circuit Board (Handset) -------------------------------- 85
13.4. Circuit Board (Charger Unit)--------------------------- 87

14 Appendix Information of Schematic Diagram --------- 88

14.1. CPU Data (Base Unit) ---------------------------------- 88
14.2. CPU Data (Handset) ------------------------------------ 90
14.3. Terminal Guide of the ICs, Transistors and

Diodes ------------------------------------------------------ 92

15 Exploded View and Replacement Parts List ----------- 93

15.1. Cabinet and Electrical Parts (Base Unit) ----------- 93
15.2. Cabinet and Electrical Parts (Handset)------------- 94
15.3. Cabinet and Electrical Parts (Charger Unit) ------- 95
15.4. Accessories and Packing Materials ----------------- 96
15.5. Replacement Part List ---------------------------------- 98