DOWNLOAD Panasonic TH-50PH12U Service Manual ↓ Size: 15.22 MB | Pages: 127 in PDF or view online for FREE

Order Number MTNC090649CE

B34 Canada: D10

GPH12D Chassis

PAGE

PAGE

1 Safety Precautions----------------------------------------------- 3

1.1. General Guidelines---------------------------------------- 3

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

2.1. Prevention of Electrostatic Discharge (ESD)

to Electrostaticy Sensitive (ES) Devices---------- 4

2.2. About lead free solder (PbF)---------------------------- 5

3 Service Navigation ----------------------------------------------- 6

3.1. Service Hint ------------------------------------------------- 6
3.2. Applicable signals ----------------------------------------- 7

4 Specifications ----------------------------------------------------- 8
5 Operating Instructions------------------------------------------ 9
6 Service Mode -----------------------------------------------------11

6.1. CAT (Computer Aided Test) mode ------------------- 11
6.2. IIC mode structure (following items value is

sample data) -----------------------------------------------14

7 Troubleshooting Guide ----------------------------------------15

7.1. Self Check--------------------------------------------------15
7.2. No Power ---------------------------------------------------17
7.3. No Picture --------------------------------------------------17

7.4. Local screen failure-------------------------------------- 18

8 Service Fixture & Tools --------------------------------------- 19

8.1. SC jig-------------------------------------------------------- 19

9 Disassembly and Assembly Instructions--------------- 20

9.1. Removal of Rear Cover -------------------------------- 20
9.2. Removal of HHH-Board -------------------------------- 20
9.3. Removal of HA-Board----------------------------------- 20
9.4. Removal of Slot Block ---------------------------------- 20
9.5. Removal of HX-Board----------------------------------- 20
9.6. Removal of DS-Board----------------------------------- 21
9.7. Removal of DN-Board ---------------------------------- 21
9.8. Removal of D-Board------------------------------------- 21
9.9. Removal of P-Board------------------------------------- 22

9.10. Removal of PF-Board ----------------------------------- 22

9.11. Removal of Speaker Terminal Block (L, R) -------- 22

9.12. Removal of SU-Board and SD-Board--------------- 22
9.13. Removal of SC-Board----------------------------------- 23
9.14. Removal of SS2-Board --------------------------------- 23
9.15. Removal of SS-Board----------------------------------- 23

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TH-50PH12U

9.16. Removal of C1-Board ----------------------------------- 24
9.17. Removal of C2-Board ----------------------------------- 24
9.18. Removal of C3-Board ----------------------------------- 24
9.19. Removal of S1-Board ----------------------------------- 25
9.20. Removal of Fan------------------------------------------- 25
9.21. Removal of Front Glass, V1, V2-Board and

Cabinet Assy ---------------------------------------------- 25

9.22. Removal of Plasma Display Panel------------------- 27

10 Measurements and Adjustments -------------------------- 31

10.1. Adjustment Procedure ---------------------------------- 31
10.2. Adjustment ------------------------------------------------- 34

11 Block Diagram --------------------------------------------------- 39

11.1. Main Block Diagram ------------------------------------- 39
11.2. Block (1 of 6) Diagram ---------------------------------- 40
11.3. Block (2 of 6) Diagram ---------------------------------- 41
11.4. Block (3 of 6) Diagram ---------------------------------- 42
11.5. Block (4 of 6) Diagram ---------------------------------- 43
11.6. Block (5 of 6) Diagram ---------------------------------- 44
11.7. Block (6 of 6) Diagram ---------------------------------- 45

12 Wiring Connection Diagram --------------------------------- 47

12.1. Wiring (1) --------------------------------------------------- 47
12.2. Wiring (2) --------------------------------------------------- 49

13 Schematic Diagram--------------------------------------------- 51

13.1. Schematic Diagram Notes ----------------------------- 51
13.2. PF-Board Schematic Diagram ------------------------ 52
13.3. P-Board (1 of 2) Schematic Diagram --------------- 53
13.4. P-Board (2 of 2) Schematic Diagram --------------- 54
13.5. V1, V2 and S1-Board Schematic Diagram -------- 55
13.6. HA-Board Schematic Diagram------------------------ 56
13.7. HX-Board Schematic Diagram------------------------ 57
13.8. HHH-Board (1 of 4) Schematic Diagram ----------- 58
13.9. HHH-Board (2 of 4) Schematic Diagram ----------- 59

13.10. HHH-Board (3 of 4) Schematic Diagram ----------- 60

13.11. HHH-Board (4 of 4) Schematic Diagram ----------- 61

13.12. DS-Board (1 of 6) Schematic Diagram ------------- 62
13.13. DS-Board (2 of 6) Schematic Diagram ------------- 63
13.14. DS-Board (3 of 6) Schematic Diagram ------------- 64
13.15. DS-Board (4 of 6) Schematic Diagram ------------- 65
13.16. DS-Board (5 of 6) Schematic Diagram ------------- 66
13.17. DS-Board (6 of 6) Schematic Diagram ------------- 67
13.18. DN-Board (1 of 7) Schematic Diagram ------------- 68
13.19. DN-Board (2 of 7) Schematic Diagram ------------- 69
13.20. DN-Board (3 of 7) Schematic Diagram ------------- 70
13.21. DN-Board (4 of 7) Schematic Diagram ------------- 71
13.22. DN-Board (5 of 7) Schematic Diagram ------------- 72
13.23. DN-Board (6 of 7) Schematic Diagram ------------- 73
13.24. DN-Board (7 of 7) Schematic Diagram ------------- 74
13.25. D-Board (1 of 4) Schematic Diagram --------------- 75
13.26. D-Board (2 of 4) Schematic Diagram --------------- 76
13.27. D-Board (3 of 4) Schematic Diagram --------------- 77
13.28. D-Board (4 of 4) Schematic Diagram --------------- 78
13.29. C1-Board (1 of 2) Schematic Diagram-------------- 79
13.30. C1-Board (2 of 2) Schematic Diagram-------------- 80
13.31. C2-Board (1 of 2) Schematic Diagram-------------- 81
13.32. C2-Board (2 of 2) Schematic Diagram-------------- 82
13.33. C3-Board (1 of 2) Schematic Diagram-------------- 83
13.34. C3-Board (2 of 2) Schematic Diagram-------------- 84
13.35. SC-Board (1 of 3) Schematic Diagram ------------- 85
13.36. SC-Board (2 of 3) Schematic Diagram ------------- 86
13.37. SC-Board (3 of 3) Schematic Diagram ------------- 87
13.38. SS-Board (1 of 2) Schematic Diagram ------------- 88

13.39. SS-Board (2 of 2) and SS2-Board Schematic

Diagram ---------------------------------------------------- 89

14 Printed Circuit Board------------------------------------------ 90

14.1. PF-Board--------------------------------------------------- 90
14.2. P-Board ---------------------------------------------------- 91
14.3. HA-Board -------------------------------------------------- 94
14.4. HX-Board -------------------------------------------------- 95
14.5. HHH-Board ------------------------------------------------ 96
14.6. V1, V2 and S1-Board ----------------------------------- 97
14.7. SS2 and H3-Board -------------------------------------- 98
14.8. DS-Board -------------------------------------------------- 99
14.9. DN-Board ------------------------------------------------- 100

14.10. D-Board --------------------------------------------------- 102

14.11. C1-Board-------------------------------------------------- 103

14.12. C2-Board-------------------------------------------------- 104
14.13. C3-Board-------------------------------------------------- 105
14.14. SC-Board ------------------------------------------------- 106
14.15. SS-Board ------------------------------------------------- 108

15 Exploded View and Replacement Parts List---------- 111

15.1. Exploded View and Mechanical Replacement

Parts List -------------------------------------------------- 111

15.2. Electrical Replacement Parts List ------------------ 111

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TH-50PH12U

1. When conducting repairs and servicing, do not attempt to modify the equipment, its parts or its materials.
2. When wiring units (with cables, flexible cables or lead wires) are supplied as repair parts and only one wire or some of the

wires have been broken or disconnected, do not attempt to repair or re-wire the units. Replace the entire wiring unit instead.

3. When conducting repairs and servicing, do not twist the Faston connectors but plug them straight in or unplug them straight

out.

4. When servicing, observe the original lead dress. If a short circuit is found, replace all parts which have been overheated or

damaged by the short circuit.

5. After servicing, see to it that all the protective devices such as insulation barriers, insulation papers shields are properly

installed.

6. After servicing, make the following leakage current checks to prevent the customer from being exposed to shock hazards.

1. Unplug the AC cord and connect a jumper between the

two prongs on the plug.

2. Measure the resistance value, with an ohmmeter,

between the jumpered AC plug and each exposed metal-
lic cabinet part on the equipment such as screwheads,
connectors, control shafts, etc.  When the exposed metal-
lic part has a return path to the chassis, the reading
should be between 1Mohm and 5.2Mohm.
When the exposed metal does not have a return path to 

the chassis, the reading must be

.

Figure 1

1. Plug the AC cord directly into the AC outlet.  Do not use

an isolation transformer for this check.

2. Connect a 1.5kohm, 10 watts resistor, in parallel with a

0.15

µF capacitors, between each exposed metallic part

on the set and a good earth ground such as a water pipe,
as shown in Figure 1 .

3. Use an AC voltmeter, with 1000 ohms/volt or more sensi-

tivity, to measure the potential across the resistor.

4. Check each exposed metallic part, and measure the volt-

age at each point.

5. Reverse the AC plug in the AC outlet and repeat each of

the above measurements.

6. The potential at any point should not exceed 0.75 volts

RMS.  A leakage current tester (Simpson Model 229 or
equivalent) may be used to make the hot checks, leakage
current must not exceed 1/2 milliamp.  In case a mea-
surement is outside of the limits specified, there is a pos-
sibility of a shock hazard, and the equipment should be
repaired and rechecked before it is returned to the cus-
tomer.

4

TH-50PH12U

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called Elec-
trostatically Sensitive (ES) Devices. Examples of typical ES devices are integrated circuits and some field-effect transistors and
semiconductor “chip” components. The following techniques should be used to help reduce the incidence of component damage
caused by electrostatic discharge (ESD).

1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any ESD on your

body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging ESD wrist strap,
which should be removed for potential shock reasons prior to applying power to the unit under test.

2. After removing an electrical assembly equipped with ES devices, place the assembly on a conductive surface such as alumi-

num foil, to prevent electrostatic charge buildup or exposure of the assembly.

3. Use only a grounded-tip soldering iron to solder or unsolder ES devices.
4. Use only an anti-static solder removal device. Some solder removal devices not classified as “anti-static (ESD protected)” can

generate electrical charge sufficient to damage ES devices.

5. Do not use freon-propelled chemicals.   These can generate electrical charges sufficient to damage ES devices.
6. Do not remove a replacement ES device from its protective package until immediately before you are ready to install it. (Most

replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil or compara-
ble conductive material).

7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material

to the chassis or circuit assembly into which the device will be installed.
Caution

Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.

8. Minimize bodily motions when handling unpackaged replacement ES devices. (Otherwise ham less motion such as the brush-

ing together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static electricity (ESD) sufficient
to damage an ES device).