KX-TG2511RUM, KX-TG2511RUN, KX-TG2511RUS, KX-TG2511RUT, KX-TG2512RUN, KX-TG2512RUS, KX-TG2521RUT, KX-TGA250RUM, KX-TGA250RUN, KX-TGA250RUS, KX-TGA250RUT - Panasonic Provideo Service Manual Supplement (repair manual). Page 2

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1 REPLACEMENT PARTS LIST ---------------------------------4

1.1. REFERENCE CHART ------------------------------------4
1.2. ORIGINAL AND NEW PARTS COMPARISON

LISTS----------------------------------------------------------4

2 Safety Precautions -----------------------------------------------5

2.1. For Service Technicians ----------------------------------5

3 Warning --------------------------------------------------------------5

3.1. Battery Caution ---------------------------------------------5
3.2. About Lead Free Solder (Pbf: Pb free) ---------------5

3.2.1. Suggested PbF Solder -------------------------------6

3.3. Discarding of P.C. Board ---------------------------------6

4 Specifications ------------------------------------------------------7
5 Technical Descriptions------------------------------------------8

5.1. Block Diagram (Base Unit) ------------------------------8
5.2. Circuit Operation (Base Unit) ---------------------------9

5.2.1. Outline----------------------------------------------------9

5.3. Block Diagram (Base Unit RF Part) ----------------- 10
5.4. Circuit Operation (Base Unit) ------------------------- 11

5.4.1. BBIC (Base Band IC: IC501) --------------------- 11
5.4.2. Flash Memory (IC601) (for KX-TG2521

only)----------------------------------------------------- 11

5.4.3. EEPROM (IC611) ----------------------------------- 11
5.4.4. Telephone Line Interface -------------------------- 11
5.4.5. Power Supply Circuit ------------------------------- 12
5.4.6. Calling Line Identification (Caller ID) ----------- 13

5.5. Block Diagram (Handset) ------------------------------ 14
5.6. Circuit Operation (Handset) --------------------------- 15

5.6.1. Outline-------------------------------------------------- 15
5.6.2. Power Supply Circuit/Reset Circuit ------------- 15
5.6.3. Charge Circuit ---------------------------------------- 15
5.6.4. Battery Low/Power Down Detector ------------- 15
5.6.5. Speakerphone---------------------------------------- 15

5.7. Circuit Operation (Charger Unit) --------------------- 16

5.7.1. Power Supply Circuit ------------------------------- 16

5.8. Signal Route ---------------------------------------------- 17

6 Location of Controls and Components ----------------- 19
7 Installation Instructions -------------------------------------- 19
8 Operating Instructions---------------------------------------- 19

8.1. For Service Hint ------------------------------------------ 19

9 Service Mode----------------------------------------------------- 20

9.1. Engineering Mode --------------------------------------- 20

9.1.1. Base Unit---------------------------------------------- 20
9.1.2. Handset ----------------------------------------------- 22

9.2. EEPROM LAYOUT (Handset)------------------------ 24

9.2.1. Scope -------------------------------------------------- 24
9.2.2. Introduction ------------------------------------------- 24
9.2.3. EEPROM contents --------------------------------- 24

9.3. Copying Phonebook Items when Repairing ------ 25
9.4. How to Clear User Setting----------------------------- 27

9.4.1. Resetting both base unit and handset --------- 27
9.4.2. Resetting only handset ---------------------------- 27

10 Troubleshooting Guide --------------------------------------- 28

10.1. Troubleshooting Flowchart ---------------------------- 28

10.1.1. Check Power ----------------------------------------- 29
10.1.2. Check Battery Charge ----------------------------- 30
10.1.3. Check Link -------------------------------------------- 31
10.1.4. Check the RF part ---------------------------------- 34
10.1.5. Check Handset Transmission-------------------- 37
10.1.6. Check Handset Reception------------------------ 37
10.1.7. Check Caller ID-------------------------------------- 37
10.1.8. Bell Reception --------------------------------------- 38
10.1.9. Check TAM Operation (for KX-TG2521

only) ---------------------------------------------------- 38

10.2. Troubleshooting by Symptom (Base Unit and

Charger Unit) --------------------------------------------- 39

10.2.1. Check Point (Base Unit)--------------------------- 39
10.2.2. Check Point (Charger Unit)----------------------- 40

10.3. Troubleshooting by Symptom (Handset) ---------- 41

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.