Panasonic TH-42LF20U, TH-47LF20U Service Manual

Order Number MTNC100773CE

FULL HD LCD Display

Model No. TH-42LF20U

TABLE OF CONTENTS

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

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

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

2.1. Prevention of Electrostatic Discharge (ESD) to Electrostatically Sensitive (ES) Devices---------- 4

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

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

3.1. Applicable signals ----------------------------------------- 6

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

6.1. Service Menu Function (1) -----------------------------11

6.2. Service Menu Function (2) -----------------------------12

6.3. Service Mode Function (1) -----------------------------13

6.4. Service Mode Function (2) -----------------------------14

7 Troubleshooting Guide----------------------------------------15 8 Disassembly and Assembly Instructions ---------------16

8.1. Flowchart for disassembly------------------------------16

8.2. Preparations -----------------------------------------------17

Model No.

PAG E PAG E

8.3. Pedestal (option) removal------------------------------ 17

8.4. Rear cover removal-------------------------------------- 17

8.5. Replacement method for main board and jack

8.6. Replacement method for Power board ------------- 19

8.7. Replacement method for AC cord bracket -------- 19

8.8. Cabinet back removal (42 type) ---------------------- 20

8.9. Cabinet back removal (47 type) ---------------------- 20

8.10. When removing the cabinet back with the

8.11. Replacement method for speakers------------------ 20

8.12. Key SW board replacement --------------------------- 20

8.13. Connector board removal ------------------------------ 21

8.14. LCD panel replacement -------------------------------- 21

8.15. Replacement method for RC+LED board---------- 22

8.16. Cabinet front replacement ----------------------------- 22

8.17. Cabinet back replacement ----------------------------- 23

9 Block Diagram --------------------------------------------------- 25

9.1. Block (1 of 2) Diagram ---------------------------------- 25

TH-47LF20U

board -------------------------------------------------------- 18

board connected ----------------------------------------- 20

TC-42LF20U / TC-47LF20U

9.2. Block (2 of 2) Diagram ---------------------------------- 26

10 Wiring Connection Diagram --------------------------------- 27

10.1. Wiring Connection Diagram (1)----------------------- 27

10.2. Wiring Connection Diagram (2)----------------------- 29

10.3. Wiring Connection Diagram (3)----------------------- 30

10.4. Wiring Connection Diagram (4)----------------------- 31

11 Exploded View and Replacement Parts List ----------- 32

11.1. Exploded View and Mechanical Replacement Parts List --------------------------------------------------- 32

11.2. Mechanical Replacement Parts List (42 inch) ---- 47

11.3. Mechanical Replacement Parts List (47 inch) ---- 48

11.4. Electrical Replacement Boards list (42 inch)------ 49

11.5. Electrical Replacement Boards list (47 inch)------ 49

11.6. Boards Layout--------------------------------------------- 49

TC-42LF20U / TC-47LF20U

1 Safety Precautions

1.1. General Guidelines

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 Fasten 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.

1.1.1. Leakage Current Cold Check

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 metallic cabinet part on the equipment such as screwheads, connectors, control shafts, etc. When the exposed metallic 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

1.1.2. Leakage Current Hot Check (See 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

0.15µF 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 sensitivity, to measure the potential across the resistor.

4. Check each exposed metallic part, and measure the voltage 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 measurement is outside of the limits specified, there is a possibility of a shock hazard, and the equipment should be repaired and rechecked before it is returned to the customer.

TC-42LF20U / TC-47LF20U

2 Warning

2.1. Prevention of Electrostatic Discharge (ESD) to Electrostatically Sensitive (ES) Devices

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called Electrostatically 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 aluminum 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 comparable 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 brushing 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).

TC-42LF20U / TC-47LF20U

2.2. About lead free solder (PbF)

Note: Lead is listed as (Pb) in the periodic table of elements. In the information below, Pb will refer to Lead solder, and PbF will refer to Lead Free Solder. The Lead Free Solder used in our manufacturing process and discussed below is (Sn+Ag+Cu). That is Tin (Sn), Silver (Ag) and Copper (Cu) although other types are available.

This model uses Pb Free solder in it’s manufacture due to environmental conservation issues. For service and repair work, we’d suggest the use of Pb free solder as well, although Pb solder may be used. PCBs manufactured using lead free solder will have the PbF within a leaf Symbol PbF stamped on the back of PCB.

Caution

• Pb free solder has a higher melting point than standard solder. Typically the melting point is 50 ~ 70 °F (30~40 °C) higher. Please use a high temperature soldering iron and set it to 700 ± 20 °F (370 ± 10 °C).

• Pb free solder will tend to splash when heated too high (about 1100 °F or 600 °C). If you must use Pb solder, please completely remove all of the Pb free solder on the pins or solder area before applying Pb solder. If this is not practical, be sure to heat the Pb free solder until it melts, before applying Pb solder.

• After applying PbF solder to double layered boards, please check the component side for excess solder which may flow onto the opposite side. (see figure below)

Suggested Pb free solder

There are several kinds of Pb free solder available for purchase. This product uses Sn+Ag+Cu (tin, silver, copper) solder. However, Sn+Cu (tin, copper), Sn+Zn+Bi (tin, zinc, bismuth) solder can also be used.

TC-42LF20U / TC-47LF20U

3 Service Navigation

3.1. Applicable signals

TC-42LF20U / TC-47LF20U

4 Specifications

Power Source 110 - 127 V AC, 50/60Hz Power Consumption

Rated Power Consumption 250 W (42 inch) 300 W (47 inch) On mode Average Power Consumption* Stand-by condition 0.1 W (42 inch) 0.1 W (47 inch)

LCD Display panel 42-inch IPS panel, 16:9 aspect ratio (42 inch) 47-inch IPS panel, 16:9 aspect ratio (47 inch) Screen size 36.6 " (930 mm) (W) × 20.5 " (523 mm) (H) × 42.0 " (1,067 mm) (diagonal) (42 inch)

(No. of pixels) 2,073,600 (1,920 (W) × 1,080 (H)) (42 inch) 2,073,600 (1,920 (W) × 1,080 (H)) (47 inch) (No. of pixels) [5,760 × 1,080 dots] [5,760 × 1,080 dots]

Operating condition

Temperature 32 °F - 104 °F (0 °C - 40 °C) Humidity 20 % - 80 %

Applicable signals

Color System NTSC, PAL, PAL60, SECAM, NTSC 4.43, PAL M, PAL N Scanning format

PC signals VGA, SVGA, XGA, SXGA

Connection terminals

AV IN VIDEO BNC 1.0 Vp-p (75-ohm)

S-VIDEO Mini DIN 4PIN Y: 1.0 Vp-p (75-ohm), C: 0.286 Vp-p (75-ohm)

AUDIO L-R RCA Pin jack × 2 0.5 Vrms HDMI 1/2 TYPE A Connector × 2 COMPONENT / RGB IN

G/Y BNC with sync 1.0 Vp-p (75-ohm)

B/P

B/CB

R/P

R/CR

AUDIO L-R RCA PIN JACK × 2 0.5 Vrms DVI-D IN DVI-D 24 Pin Compliance with DVI Revision 1.0

AUDIO Stereo mini jack (M3) × 1 0.5 Vrms, Shared with PC IN PC IN High-Density Mini D-sub 15 Pin G with sync 1.0 Vp-p (75-ohm)

AUDIO Stereo mini jack (M3) × 1 0.5 Vrms, Shared with PC IN SERIAL External Control Terminal

Sound

Speakers 2.0” (50 mm) × 3.6” (90 mm) × 2 pcs Audio Output 10 W [5 W + 5 W] (10 % THD)

Accessories Supplied

Remote Control Transmitter N2QAYB000535 Batteries AA Size × 2 Clamper TMME289 × 3

Dimensions (W × H × D) 38.2" (968 mm) × 22.1" (561 mm) × 4.0" (101 mm)

Mass (weight) approx. 39.7 lbs (42 inch) approx. 50.7 lbs (47 inch)

* Based on IEC 62087 Ed.2 section 11.6.1 measurement method.

Note:

• Design and specifications are subject to change without notice. Mass and dimensions shown are approximate.

200 W (42 inch) 255 W (47 inch)

40.9 " (1,040 mm) (W) × 23.0 " (585 mm) (H) × 46.9 " (1,193 mm) (diagonal) (47 inch)

525 (480) / 60i 60p, 625 (575) / 50i 50p, 750 (720) / 60p 50p, 1125 (1080) /

60i 60p 50i 50p 24p 25p 30p 24sF, 1250 (1080) / 50i

UXGA ..... (compressed)

Horizontal scanning frequency 30 - 110 kHz Vertical scanning frequency 48 - 120 Hz

BNC 0.7 Vp-p (75-ohm)

Content Protection Compatible with HDCP 1.1

G without sync 0.7 Vp-p (75-ohm) B:0.7 Vp-p (75-ohm) R:0.7 Vp-p (75-ohm) HD / VD:1.0 - 5.0 Vp-p (high impedance)

D-sub 9 Pin RS-232C compatible

(42 inch)

38.2" (968 mm) × 22.1" (561 mm) × 4.0" (101 mm) (47 inch)

5 Operating Instructions

TC-42LF20U / TC-47LF20U

6 Service Mode

6.1. Service Menu Function (1)

TC-42LF20U / TC-47LF20U

6.2. Service Menu Function (2)

6.3. Service Mode Function (1)

TC-42LF20U / TC-47LF20U

6.4. Service Mode Function (2)

7 Troubleshooting Guide

TC-42LF20U / TC-47LF20U

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