KX-PRX120UAW, KX-PRXA10RUW - Panasonic Telephone Service Manual (repair manual). Page 2

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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

2.2.1. Suggested PbF Solder -------------------------------5

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

4.2.1. Outline----------------------------------------------------8
4.2.2. Power Supply Circuit ---------------------------------9
4.2.3. Telephone Line Interface -------------------------- 10
4.2.4. Transmitter/Receiver ------------------------------- 10

4.3. Block Diagram (Handset) ------------------------------ 11

4.3.1. KX-PRXA10------------------------------------------- 11

4.4. Circuit Operation (Charger Unit) --------------------- 13

4.4.1. Power Supply Circuit ------------------------------- 13

4.5. Signal Route----------------------------------------------- 14

5 Location of Controls and Components------------------ 16
6 Installation Instructions--------------------------------------- 16
7 Operating Instructions ---------------------------------------- 16

7.1. For Service Hint ------------------------------------------ 16

8 Service Mode ----------------------------------------------------- 17

8.1. Engineering Mode---------------------------------------- 17

8.1.1. Base Unit ---------------------------------------------- 17
8.1.2. Handset ------------------------------------------------ 18

8.2. EEPROM LAYOUT (Handset) ------------------------ 19

8.3. Copying User Data when Repairing ---------------- 19

8.3.1. Phonebook ------------------------------------------- 19
8.3.2. Other User Data ------------------------------------- 19

8.4. How to Clear User Setting----------------------------- 20

8.4.1. Resetting both base unit and handset --------- 20
8.4.2. Resetting only handset ---------------------------- 21

9 Troubleshooting Guide --------------------------------------- 22

9.1. Troubleshooting Flowchart ---------------------------- 22

9.1.1. Check Power----------------------------------------- 24
9.1.2. Check DECT Link----------------------------------- 26
9.1.3. Check Touch Panel--------------------------------- 28
9.1.4. Check DECT RF part ------------------------------ 29
9.1.5. Check Handset Transmission-------------------- 30
9.1.6. Check Handset Reception------------------------ 31
9.1.7. Check TAM Operation Part ----------------------- 33
9.1.8. Check SD Card Part ------------------------------- 34
9.1.9. Check Camera Part -------------------------------- 34

9.1.10. Check Sensor Part --------------------------------- 35

9.1.11. Check WiFi, BT Part ------------------------------- 35

9.1.12. Check Battery Charge ----------------------------- 35

9.2. Troubleshooting by Symptom (Base Unit 

and Charger Unit)---------------------------------------- 36

9.2.1. Check Point (Base Unit)--------------------------- 36
9.2.2. Check Point (Charger Unit)----------------------- 38

9.3. Troubleshooting by Symptom (Handset) ---------- 39
9.4. Function Check at Factory Mode -------------------- 40

10 Disassembly and Assembly Instructions -------------- 43

10.1. Disassembly Instructions ------------------------------ 43

10.1.1. Base Unit---------------------------------------------- 43

This service information is designed for experienced repair technicians only and is not designed for use by the general 
public. It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting 
to service a product. Products powered by electricity should be serviced or repaired only by experienced professional 
technicians. Any attempt to service or repair the product or products dealt with in this service information by anyone 
else could result in serious injury or death.

There are special components used in this equipment which are important for safety. These parts are marked by 
in the Schematic Diagrams, Circuit Board Diagrams, Exploded Views and Replacement Parts List. It is essential that 
these critical parts should be replaced with manufacturer's specified parts to prevent shock, fire or other hazards.
Do not modify the original design without permission of manufacturer.

If lead free solder was used in the manufacture of this product, the printed circuit boards will be marked PbF.
Standard leaded, (Pb), solder can be used as usual on boards without the PbF mark.
When this mark does appear, please read and follow the special instructions described in this manual on the 
use of PbF and how it might be permissible to use Pb solder during service and repair work.

L When you note the serial number, write down all 11 digits. The serial number may be found on the bottom of the unit. 
L The illustrations in this Service Manual may vary slightly from the actual product.