Panasonic TH-37LRU20 Service manual

Order Number MTNC100663CE

B01 Canada: B61

Hospitality LCD HDTV

Model No. TH-37LRU20

LA11 Chassis

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. Service Hint ------------------------------------------------- 6

3.2. Applicable signals ----------------------------------------- 6

4 Specifications ----------------------------------------------------- 7 5 Service Mode ------------------------------------------------------ 8

5.1. How to enter into Service Mode ----------------------- 8

5.2. SRV-TOOL-------------------------------------------------- 9

5.3. Hotel mode-------------------------------------------------10

5.4. Data Copy by SD Card----------------------------------11

6 Troubleshooting Guide----------------------------------------14

6.1. Check of the IIC bus lines ------------------------------14

6.2. Power LED Blinking timing chart ---------------------15

PAGE PAGE

6.3. No Power--------------------------------------------------- 15

7 Disassembly and Assembly Instructions---------------16

7.1. Removal of Rear Cover --------------------------------16

7.2. Removal of Pedestal Assy-----------------------------16

7.3. Removal of AC Cord ------------------------------------16

7.4. Removal of Control Panel Assy ----------------------16

7.5. Removal of P-Board------------------------------------- 16

7.6. Removal of TA-Board-----------------------------------16

7.7. Removal of Side AV Bracket-------------------------- 17

7.8. Removal of A-Board------------------------------------- 17

7.9. Removal of Speaker Unit (L, R) ----------------------17

7.10. Removal of Cabinet Assy and V-Board ------------ 18

7.11. Removal of LCD Panel ---------------------------------18

8 Measurements and Adjustments--------------------------20

8.1. Voltage chart of A-board -------------------------------20

8.2. Picture level adjustment (RF) -------------------------20

9 Block Diagram ---------------------------------------------------21

9.1. Main Block Diagram ----------- -------------------------21

TH-37LRU20

9.2. Block (1 of 2) Diagram--------------- -------------------22

9.3. Block (2 of 2) Diagram--------------- -------------------23

10 Wiring Connection Diagram---------------------------------25

10.1. Wiring ------------------------------------------------------- 25

11 Schematic Diagram---------------------------------------------27

11.1. Schematic Diagram Notes ---------------------------- - 27

11.2. P-Board (1 of 2) Schematic Diagram ------ ---------28

11.3. P-Board (2 of 2) Schematic Diagram ------ ---------29

11.4. A-Board (1 of 19) Schematic Diagram--------------30

11.5. A-Board (2 of 19) Schematic Diagram--------------31

11.6. A-Board (3 of 19) Schematic Diagram--------------32

11.7. A-Board (4 of 19) Schematic Diagram--------------33

11.8. A-Board (5 of 19) Schematic Diagram--------------34

11.9. A-Board (6 of 19) Schematic Diagram--------------35

11.10. A-Board (7 of 19) Schematic Diagram--------------36

11.11. A-Board (8 of 19) Schematic Diagram--------------37

11.12. A-Board (9 of 19) Schematic Diagram--------------38

11.13. A-Board (10 of 19) Schematic Diagram ------------39

11.14. A-Board (11 of 19) Schematic Diagram ------------40

11.15. A-Board (12 of 19) Schematic Diagram ------------41

11.16. A-Board (13 of 19) Schematic Diagram ------------42

11.17. A-Board (14 of 19) Schematic Diagram ------------43

11.18. A-Board (15 of 19) and V-Board Schematic Diagram-----------------------------------------------------44

11.19. A-Board (16 of 19) Schematic Diagram ------------45

11.20. A-Board (17 of 19) Schematic Diagram ------------46

11.21. A-Board (18 of 19) Schematic Diagram ------------47

11.22. A-Board (19 of 19) Schematic Diagram ------------48

12 Printed Circuit Board ------------------------------------------49

12.1. P-Board-----------------------------------------------------49

12.2. A-Board-----------------------------------------------------51

12.3. V-Board-----------------------------------------------------53

13 Exploded View and Replacement Parts List----------- 55

13.1. Exploded View and Mechanical Replacement Parts List ---------------------------------------------------55

13.2. Electrical Replacement Parts List--------------------55

TH-37LRU20

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. Wh en 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. Wh en conducting repairs and servicing, do not twist the Fasten connec tors but plug them straight in or unplug them straight out.

4. Wh en servicing, observe the original lead dress. If a short circuit is found, replace all parts which have been overhe ated or damaged by the short circuit.

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

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

1.1.1. Leakage Current Cold Check

1. Unplug the AC cord and co nnect 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.

TH-37LRU20

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 asse mbly on a conductive surfac e 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 precaution s.

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).

TH-37LRU20

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.

TH-37LRU20

3 Service Navigation

3.1. Service Hint

Board Name Function

TA-Board Band Pass Filter, Frequency Shift Keying Receiver, Frequency

A-Board Speaker out, AV Terminal, HDMI in, SD Card, PC in,

V-Board Remote Receiver, LED P-Board Power (AC/DC), DC-DC Control Panel Assy Control Button, Power switch

Shift Keying switch, MPU Non serviceable TA-Board should be exchanged for service.

Digital Signal Processor, Peaks sLD, Tuner

Non serviceable Control Panel Assy should be exchanged for service.

3.2. Applicable signals

4 Specifications

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

Rated Power Consumption 159 W On mode Average Power Consumption* Standby condition 0.8 W

Display panel

Aspect Ratio 16:9 Visible screen size 37" class (37.0 inches measured diagonally) (W × H × Diagonal) 32.2 " × 18.1 " × 37.0 " (819 mm × 460 mm × 940 mm) (No. of pixels) 1,049,088 (1,366 (W) × 768 (H)) [4,098 × 768 dots]

Sound

Speaker 1-way 2 speakers slim under SP System Audio Output 20 W [10 W + 10 W] (10 % THD)

PC signals VGA, SVGA, XGA, WXGA, SXGA

Channel CapabilityATSC/NTSC (Digital/Analog) Operating Conditions Temperature: 32 °F - 95 °F (0 °C - 35 °C)

Connection Terminals

VIDEO IN 1-2 VIDEO: RCA PIN Type × 1 1.0 V [p-p] (75-ohm)

COMPONENT IN Y: 1.0 V [p-p] (including synchronization)

HDMI 1-3 TYPE A Connector × 3 PC D-SUB 15PIN: R,G,B / 0.7 V [p-p] (75-ohm)

SERIAL CTRL M3 Jack × 1 (RS232C) DATA/MTI RJ-11C (6pin)

Audio out M3 JACK × 1 0.5 V [rms] (high impedance) Card slot SD CARD slot × 1 DIGITAL AUDIO OUT PCM / Dolby Digital, Fiber Optic

FEATURES 3D Y/C FILTER, CLOSED CAPTION,

Dimensions (W × H × D)

Including TV stand 36.1 " × 24.5 " × 12.1 " (915 mm × 622 mm × 307 mm) TV Set only 36.1 " × 22.8 " × 3.5 " (915 mm × 577 mm × 87 mm)

Mass

Including TV stand 36.9 lb. (16.7 kg) NET TV Set only 28.7 lb. (13.0 kg) NET

* 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.

84 W

Horizontal scanning frequency 31 - 69 kHz Vertical scanning frequency 59 - 86 Hz VHF/ UHF: 2 - 69, CATV: 1 - 135 (support MPEG4 H.264 decode)

Humidity: 20 % - 80 % RH (non-condensing)

AUDIO L-R: RCA PIN Type × 2 0.5 V [rms]

, PR: ±0.35 V [p-p]

AUDIO L-R: RCA PIN Type × 2 0.5 V [rms]

HD, VD / 1.0 - 5.0 V [p-p] (high impedance)

• Multiple Television Interface (MTI)

• Nintendo Controller Power (pin3: DC12V / 30mA (max))

• SNES Controller

V-Chip, Vesa compatible, Integrated Pro: Idiom

TH-37LRU20

5 Service Mode

5.1. How to enter into Service Mode

5.1.1. Set "Hotel Mode" Off

Service Mode can not be entered if Hotel mode is "On" (Activating). Hotel Mode should be set to "Off" by using only Remote Control as following procedure.

1. Press [MENU], [G], [Y] and [0] buttons on the remote control by turns to display "Hotel Mode setup menu".

2. Select the item "Mode" and set "Off" status.

3. Select the item "Save" and press [OK] button.

4. Disconnect the AC cord from wall outlet, or press and hold the [POWER] button at right side on the main unit for 10 seconds or more.

5.1.2. Enter into Service Mode

While pressing [VOLUME ( - )] button of the main unit, press [INFO] button of the remote control three times within 2 seconds.

5.1.3. Key command

[1] button...Main items Selection in forward direction [2] button...Main items Selection in reverse direction [3] button...Sub items Selection in forward direction [4] button...Sub items Selection in reverse direction [VOL] button...Value of sub items change in forward direction ( + ), in reverse direction ( - )

5.1.4. Contents of adjustment mode

• Value is shown as a hexadecimal number.

• Preset value differs depending on models.

• After entering the adjustment mode, take note of the value in each item before starting adjustment.

Main item Sub item Sample Data Remark

ADJUST CONTRAST 000

COLOR 34 TINT 00 SUB-BRT 800 BACKLGT 51D B-Y-G 38 R-Y-A 10 V COM 000

WB-ADJ R-GAIN FF

G-GAIN F8 B-GAIN FC R-CENT 7E G-CENT 80 B-CENT 82

OPTION Boot ROM Factory Preset.

STBY-SET 00 EMERGENCY ON CLK MODE 00 CLOCK 000 EDID-CLK MID

SRV-TOOL 00 See next.

5.1.5. How to exit

Switch off the power with the [POWER] button on the main unit or the [POWER] button on the remote control.

TH-37LRU20

5.2. SRV-TOOL

5.2.1. How to access

1. Select [SRV-TOOL] in Service Mode.

2. Press [OK] button on the remote control.

5.2.2. Display of SOS History

SOS History (Number of LED blinking) indication. From left side; Last SOS, before Last, three occurrence before, 2nd occurrence after shipment, 1st occurrence after shipment. This indication except 2nd and 1st occurrence after shipment will be cleared by [Self-chec k indication and forced to factory shipment setting].

5.2.3. POWER ON TIME/COUNT

Note : To display TIME/COUNT menu, highlight position, then press MUTE for 3 seconds. Time : Cumulative power on time, indicated hour : minute by decimal Count : Number of ON times by decimal Note : This indication will not be cleared by either of the self-checks or any other command.

5.2.4. Exit

1. Disconnect the AC cord from wall outlet, or press and hold the TV's [POWER] button for 10 seconds or more.

TH-37LRU20

5.3. Hotel mode

1. Purpose Restrict a function for hotels.

2. To display Hotel mode setup menu Press [MENU], [G], [Y] and [0] buttons on the remote control by turns.

Then, the Hotel mode setup menu is displayed.

item Function Mode Select hotel mode off/on TA Ctrl Sets TA (Terminal Adaptor) status. (Internal/

External/Off) Internal: Use Internal TA External: Use External TA

Initial input Selects Input when the TV is turned on.

Does not operate when input from TA to the TV is prohibited.

(-/RF/HDMI 1-3/Component/Video1-2/PC) Initial channel Sets the channel at power-on. Initial volume Sets the volume level at power-on. (0-100)

Does not operate when control from TA to

the TV is prohibited. Max.volume Sets the maximum volume level. (0-100) OSD Ctrl Limits the OSD display. (Off/Pattern1)

Pattern 1: "Recall" and "Shut-off notification"

messages are not displayed at power-on.

Also displayed when "Pattern 1" is spec ified

as the display command from TA. Button lock Limits the TV panel button operation. (Off/

Pattern1/All)

All: All buttons are not available.

Pattern 1: Only INPUT and PO WER buttons

are available. Power ctrl Sets the screen condition when the AC

power is switched on. (Off/On)

Off: Starts up in last screen.

ON: Starts up in screen On. Remote Switches Operation guide according to

remote control. (Panasonic/Others) CC reset Sets CC setting status. (Off/On)

Off: Saves the last settings.

On: Resets all CC settings to defaults. Lock reset Sets Lock setting status. (Off/On)

Off: Saves the last settings.

On: Resets all Lock settings to defaults. CC Priority CC Contents priority setting. (708/608)

Note: This item was introduced by running

change.

3. Setting for each items Select item by [UP]/[DOWN] button on the remote control and change the setting by [LEFT]/[RIGHT] button on the remote control. After the setting, select "Save" and press [OK] button on the remote control to store.

4. To exit the Hotel mode setup menu Disconnect the AC cord from wall outlet, or press and hold the [POWER] button at right side on the main unit for 10 seconds or more.

5. Explain the Hotel mode setup menu

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5.4. Data Copy by SD Card

5.4.1. Purpose

(a) Board replacement (Copy the data when exchanging A-board):

When exchanging A-board, the data in original A-board can be copied to SD card and then copy to new A-board.

(b) Hotel (Copy the data when installing a number of units in hotel or any facility):

When installing a number of units in hotel or any facility, the data in master TV can be copied to SD card and then copy to other TVs.

5.4.2. Preparation

Make pwd file as startup file for (a) or (b) in a empty SD card.

1. Insert a empty SD card to your PC.

2. Right-click a blank area in a SD card window, point to New, and then click Text Document. A new file is created by default (New Text Document.txt).

3. Rig ht-click the new text document that you just created and select rename, and then change the name and exten sion of the file to the following file name for (a) or (b) and press ENTER.

File name:

(a) For Board replacement : boardreplace.pwd (b) For Hotel : hotel.pwd

Note:

Please make only one file to prevent the operation error. No any other file should not be in SD card.

TH-37LRU20

5.4.3. Data copy from TV set to SD Card

1. Turn on the TV set.

2. Insert SD card with a startup file (pwd file) to SD slot. On-screen Display will be appeared according to the startup file automatically.

3. Input a following password for (a) or (b) by using remote control.

(a) For Board replacement : 2770

(b) For Hotel : 4850 Data will be copied from TV set to SD card. It takes around 2 to 6 minutes maximum for copying.

4. After the completion of copying to SD card, remove SD card from TV set.

5. Turn off the TV set.

Note:

Following new folder will be created in SD card for data from TV set.

(a) For Board replacement : user_setup (b) For Hotel : hotel

5.4.4. Data copy from SD Card to TV set

1. Turn on the TV set.

2. Insert SD card with Data to SD slot. On-screen Display will be appeared according to the Data folder automatically.

3. Input a following password for (a) or (b) by using remote control.

(a) For Board replacement : 2771 (b) For Hotel : 4851

Data will be copied from SD card to TV set.

4. After the completion of copying to SD card, remove SD card from TV set.

(a) For Board replacement : Data will be deleted after copying (Limited one copy). (b) For Hotel : Data will not be deleted and can be used for other TVs.

5. To save Data and exit: press and hold the TV's [POWER] button for 10 seconds or more then release.

Note:

1. Depending on the failure of boards, function of Data copy for board replacement does not work.

2. This function can be effective amon g the same model numbers.

TH-37LRU20

6 Troubleshooting Guide

Use the self-check function to test the unit.

1. Checking the IIC bus lines

2. Power LED Blinking timing

6.1. Check of the IIC bus lines

6.1.1. Set "Hotel Mode" Off

SELF CHECK can not be entered if Hotel mode is "On" (Activating). Hotel Mode should be set to "Off" by using only Remote Control as following procedure.

1. Press [MENU], [G], [Y] and [0] buttons on the remote control by turns to display "Hotel Mode setup menu".

2. Select the item "Mode" and set "Off" status.

3. Select the item "Save" and press [OK] button.

4. Disconnect the AC cord from wall outlet, or press and hold the [POWER] button at right side on the main unit for 10 seconds or more.

6.1.2. Enter into SELF CHECK

Self-check indication only: Produce TV reception screen, and while pressing [VOLUME ( - )] button on the main unit, press [OK] button on the remote control for more than 3 seconds. Self-check indication and forced to factory shipment setting: Produce TV reception screen, and while pressing [VOLUME ( - )] button on the main unit, press [MENU] button on the remote control for more than 3 seconds.

6.1.3. Exit

Disconnect the AC cord from wall outlet, or press and hold the TV's [POWER] button for 10 seconds or more.

6.1.4. Screen display

6.1.5. Check Point

Confirm the following parts if NG was displayed.

DISPLAY Ref.No. Description P.C.B. Peaks IC8001 Peaks sLD A-BOARD TUN TU8300 TUNER A-BOARD FE IC8300 DEMO DULATOR A-BOARD ADAM IC8001 sLD A-BOARD AVSW IC3000 AUDIO VIDEO SWITCH A-BOARD STBY IC8001 sLD/STM A-BOARD MEM1 IC8950 EEPROM (sLD) A-BOARD MEM2 IC1101 EEPROM (STM) A-BOARD TEMP IC9980 TEMP SENSOR A-BOARD MEM3 IC in LCD PANEL EEPROM (Panel) LCD PANEL DCDC IC4800 DC-DC (T-con) A-BOARD DAC IC4802 DAC (T-con) A-BOARD FRSC IC9004 MPU (TA) TA-BOARD PRID IC8305 Pro: Idiom TA-BOARD

6.2. Power LED Blinking timing chart

1. Subject Information of LED Flashing timing chart.

2. Contents When an abnormality has occurred to the unit, the protection circuit operates and resets to the stand by mode. At this time, the defective block can be identified by the number of blinks of the Power LED on the front panel of the unit.

TH-37LRU20

6.3. No Power

First check point There are following 2 states of No Power indication by power LED.

1. No lit.

2. Red is lit then turns red blinking a few seconds later. (See 6.2.)

TH-37LRU20

7 Disassembly and Assem-

bly Instructions

• To disassembl e P.C.B., wait for 1 minute after power was off for discharge from electrolysis capacitors.

• , , , , and marks indicate screw positions.

7.1. Removal of Rear Cover

1. Remove screws (×14 , ×4 , ×2 , ×4 ) and then remove the Rear Cover.

7.4. Removal of Control Panel Assy

1. Remove 2 screws and then remove the Control Panel Assy.

2. Disconnect the connector (K1).

7.5. Removal of P-Board

1. Disconnect the connectors (P1, P2, P5, P6).

2. Remove 6 screws.

3. Remove 2 hooks.

4. Remove P-Board from the Bracket IP.

7.2. Removal of Pedestal Assy

1. Remove the Pedestal Assy.

7.3. Removal of AC Cord

1. Disconnect the connector (P1).

2. Remove the AC Cord from the AC Cord Bracket.

7.6. Removal of TA-Board

1. Remove 1 nut and then remove the lock washer and the washer.

2. Remove 2 screws and then remove the Tuner Mount Metal.

TH-37LRU20

3. Remove the Tuner Extension Adapter.

4. Remove the analog-digital tuner-cable from TA-Board.

5. Disconnect the connector (TA5).

6. Remove 3 screws and then remove TA-Board.

7.7. Removal of Side AV Bracket

1. Remove 1 screw ( ).

2. Remove 1 screw ( ).

3. Remove 2 hooks and then remove the Side AV Bracket.

4. Remove the analog-digital tuner-cable from A-Board.

5. Disconnect the connectors (A02, A5, A09, A10, A12).

6. Remove the LVDS Cable from the connector (A14).

7. Remove 6 screws and then remove A-Board.

7.9. Removal of Speaker Unit (L, R)

1. Connected terminal hook is pushed, and the speaker lead in 4 places is pulled out.

7.8. Removal of A-Board

1. Remove the Side AV Bracket. (Refer to Removal of Side AV Bracket)

2. Remove 1 screw ( ).

3. Remove 3 screws ( ) and then remove the A-Board Shield Top.

2. Remove the Speaker Unit (L, R) from the Speaker Bracket.

TH-37LRU20

7.10. Removal of Cabinet Assy and V-Board

1. Remove the Pedestal Assy. (Refer to Removal of Pedestal Assy)

2. Remove the Control Panel Assy. (Refer to Removal of Control Panel Assy)

3. Remove 4 screws and then remove the Speaker Unit Block (L, R).

4. Disconnect the connector (A10).

5. Remove 10 screws and then remove the LCD Panel Block.

7.10.2. Removal of V-Board

1. Remove 1 screw.

2. Remove 1 hook and then remove the LED Panel from VBoard.

3. Disconnect the connector (V10).

7.11. Removal of LCD Panel

1. Remove the Pedestal Assy. (Refer to Removal of Pedestal Assy)

2. Remove the AC Cord. (Refer to Removal of AC Cord)

3. Remove the Control Panel Assy. (Refer to Removal of Control Panel Assy)

4. Remove the Side AV Bracket. (Refer to Removal of Side AV Bracket)

5. Disconnect the connectors (A02, A09, A10, A12).

6. Remove the LVDS Cable from the connector (A14).

7. Remove 2 screws ( ).

8. Remove 7 screws ( ).

9. Remove the TA-Board Block and A-Board.

7.10.1. Removal of Cabinet Assy

1. Remove 1 screw and then remove the V-Board Block from the Cabinet Assy.

10. Remove 4 screws and then remove the Speaker Unit Block (L, R).

TH-37LRU20

11. Remove 10 screws.

12. R emove the VESA Metal Top.

13. R emove the Metal Bracket A.

14. Disconnect the connectors (P5, P6).

15. R emove 1 screw ( ).

16. R emove 9 screws ( ).

17. R emove the Metal Support (L).

18. R emove the P-Board Block.

22. Remove 2 screws ( ).

23. Remove 2 screws ( ) and then remove the Metal Bracket Top.

24. Remove the Panel LVDS Barrier.

25. Remove the LVDS Cable from the connector (CN1).

26. Remove 6 screws.

27. Remove the LCD Panel from the Cabinet Assy.

19. R emove the Metal Bracket P.

20. R emove 1 screw ( ).

21. Remove 2 screws ( ) and then remove the Metal Bracket Bottom Block.

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8 Measurements and Adjustments

8.1. Voltage chart of A-board

VOLTAGE TEST POINT SPECIFICATION

SUB1.8V TP5601 1.74 - 1.90 SUB1.2V TP5600 1.18 - 1.32 SUB3.3V TP5602 3.19 - 3.46

SUB5V TP5200 4.9 - 5.1 SUB9V TP5220 8.82 - 9.18 STB5V TP5400 4.9 - 5.1

(Reception state)

8.2. Picture level adjustment (RF)

Instrument Name Remarks

1. REMOTE TRANSMITTER

2. Ex. Signal (Sprit color bar)

Adjustment or Inspection Procedure Remarks

< procedure >

1. Receive the Sprit color bar. (Screen mode: ZOOM or FULL Picture mode: DYNAMIC AI: OFF AI Picture: OFF) *BACK LIGHT +30

< Inspection >

1. Enter Service mode, and go to "ADJUST-CONTRAST" to adjust the picture level. Volume UP/DOWN key makes GAIN displayed under PICTURE to set.

(The Sprit Color Bar Pattern)

9 Block Diagram

(LED:9TIMES)

(LED:4TIMES)

(LED:7TIMES)

(LED:1TIMES)

HOT COLD

(LED:3TIMES)

9.1. Main Block Diagram

INTERNAL TA

FSK RECEIVER

MPU

12V

SPEAKER(L)

SPEAKER(R)

RF OUT

TA5

RF OUT

TA5

(SIDE)

A12

DATA

MTI

RF IN

STB 12V

EXTERNAL TA

RF IN

FSK SWITCH

TV DATA OUT

MTI DATA

TV CLK/IR

DIGITAL SIGNAL PROCESSOR

IFD_OUT

TUNER

SIF_OUT

TV DATA OUT

TV DATA IN

TV CLK/IR

STB+5.8V

TMDS DATA

HDMI1

TMDS DATA

HDMI2

TMDS DATA

HDMI3

(SIDE)

COMPONENT

AV1

AV2

(SIDE)

Y/PB/PR

L/R

V L/R

L/R

R/G/B/H/V

AUDIO OUT

AUDIO

AMP

OPTICAL

AUDIO OUT

AUDIO

OUT

PWM

SOS DET

ATSC DEMODURATOR

AV SW

L/R

DTV_L/R

Y/PB/PR, R/G/B/H/V CVBS

DVB_CVBS

NAND FLASH

TS Parallel

CPU BUS

(A Chip)

SIF

HDMI I/F RECEIVER

A/D CONVERTOR

D/A CONVERTOR

CPU BUS I/F

PRO:Ideom

DESCRAMBLE

(D Chip)

AUDIO PROCESSOR

PWM

OPTICAL OUT

VIDEO PROCESSOR

TS Parallel

LVDS DATA

HOT START

(DAC_ENB)

SUB_ON

KEYSCAN

Peaks sLD

(STM)

INV_ON

(LED:1TIMES)

BL_SOS

(MTI)

TV CLK/IR

TV DATA IN

TV DATA OUT

TV DATA IN

TV DATA OUT

(LED:3TIMES)

PANEL POWER SOS

SD CARD DATA

SOUND SOS

(LED:9TIMES)

INV_PWM

STB3.3V

STB_RESET

POWER LED(R)

REMOTE IN

C.A.T.S. SENSOR

SUB 3.3V SENSE (LED:7TIMES)

DTV12V SENSE (LED:4TIMES)

TH-37LRU20

EEPROM

SD CARD DATA

DTV12V

ANALOG-ASIC

INV_PWM

STB5V

SUB5V

OVP_DET

EEPROM

SOS DET

RXD TXD

SERIAL CRTL DATA

STB+3.3V

SD CARD

SLOT

RS232C

POWER LED

REMOTE RECEIVER C.A.T.S. SENSOR

A10

STB+3.3V

V10

POWER LED

REMOTE RECEIVER

C.A.T.S. SENSOR

POWER SUPPLY

RECTIFIER

LINE FILTER

LIVE

PFC CONTROL

NEUTRAL

AC CORD

RECTIFIER

POWER CONTROL

PROCESS VOLTAGE RECTIFIER

STANDBY VOLTAGE RECTIFIER

HOT COLD

17V

DTV12V

+5.8VS

INVERTER CURCUIT

CONTROL PANEL ASSY

INVERTER POWER CONTROL

P5,P6

OPERATION BUTTON

SOUND17V

VOLTAGE DROP

A02

PANEL POWER SOS

(LED:3TIMES)

DCDC

AVDD13.7V

SOUND17V

DTV12V

RELAY

SUB_ON

+5.8VS

A09

5.8V

INV_PWM

INV_ON

BL_SOS

STB5.8V

DTV12V

DVDD2.5V

DCDC

SUB9V

DCDC

SUB3.3V

DCDC

SUB1.8V

DCDC

SUB1.2V

DCDC

STB5V

DCDC

TUNER5V

DCDC

SUB5V

AVDD13.7V

DVDD2.5V

SUB9V

SUB3.3V

SUB1.8V

SUB1.2V

STB5V

TUNER5V

SUB5V

OVP_DET

ERROR DET

OVER VOLTAGE

DVDD2.5V

AVDD13.7V

VOFF2-6V

A14

CONTROL

PANEL

BACK LIGHT

VCON31V

D/A

LVDS DATA

VREF_1-12

LCD PANEL

TH-37LRU20

HOT

COLD

(LED:1TIMES)

HOT

(LED:3TIMES)

9.2. Block (1 of 2) Diagram

INTERNAL TA

JK9002

T9001

JK9001

POWER SUPPLY

D7030

F7001

T5AL AC250V

BAND PASS FILTER

IC9005

FSK SW

RECTIFIER

LIVE

FSK RECEIVER

T7201

LINE FILTER

NEED

HOLDER

IC9006

NEUTRAL

AC CORD

IC9002

BUFFER

CONTROL

IC7201

D7407

RECTIFIER

LF7001 LF7002 LF7003

AC120V

PFC

JK3301D

AV1_L

AV1_R

IC3000

COMPONENT

Y/PB/PR

L/R

AV1

L/R

AV2

Y/C/V

L/R

R/G/B/H/V

V SUB5V

SUB9V

DVB_CVBS

D5400

D4824

PA4800

IC4803

Q4804,05

-6V GEN.

LEVEL SHIFT

Q4803

AV1

AV2_V

AV2_L

AV2_R

AV SW

STB5V

VOLTAGE DROP ERROR DET

IC4800

+13.7V

+2.5V

AVDD13.7V

MAIN OUT

Y/PB/PR, R/G/B/H/V CVBS

DTV

DCDC_CTL

OVP DET

TCON12V

COMPONENT

AV1_Y

AV1_PB

AV1_PR

SUB3.3V

SUB1.8V

+1.8V

SUB1.2V

+1.2V

IC5416

STB5V

D5401

D4826

AVDD13.7V

DVDD2.5V

IIC TCON

VREF_1-12

LVDS DATA

IIC TCON

JK9003

DIGITAL SIGNAL PROCESSOR

ANT IN

TU8300 TUNER

Q9003

IC9001

RXD

TXD

RTB CHANGE

TV_DATA_OUT

TV_DATA_IN

TV_CLK

TV_IR

IC9004

MPU

BUFFER

VCC

IC9012

MPF5V

TA5

TV_DATA_OUT

TV_DATA_IN

TV_CLK

TV_IR

LN_REG_ON

STB5.8V

IC9011

FS5V

VCC

IC9010

RL7101

HOT

PHOTO COUPLER

D7204

Q7301

Q7251,52

OVP

D7253

VCC

RESONANCE

IC7301

POWER CONTROL

VCC

Q7701

RL7102

RL7103

CF7101

D7404

D7403

T7401

D7603

IC7401

STB CONTROL

PC7401

PHOTO COUPLER

CLK2

VCC

H/V DRV1

H/V DRV2

IC7801

INV VOLTAGE SUPPLY/FET DRIVER

OUT1

OUT2

CLK1

Q7803,04

H/V GEN

Q7801,02

H/V GEN

12V

PC7301

PC7701

TUNER_6V

IC7601

STB ERROR DET

HOT

COLD

T7301

RELAY ON/OFF

12V

T7803

T7801

COLD

STBM5V

D7503

D7552

IC9007

14V

D7860

D7861

D7863

D7864

Q7032

IC7851

VCC

DRV1

DRV2

D7830

D7831

17V

DTV12V

IC7501

12V ERROR DET

Q7702

ON/OFF

INVERTER POWER CONTROL

BURST

ALARM

PRO_L

PRO_H

D7855

IC9008

ENA

OVP

Q7754

CONTROL PANEL ASSY

OPERATION BUTTON

(LED:1TIMES)

D7856

D7862

D7865

STB5V

TUNER_6V

INV_PWM

KEY3

KEY

SOUND17V

DTV12V

5.8VS

5.8V

TUNER_6V

SUB_ON

INV_ON

BL_SOS

TV_DATA_OUT

STB5.8V

TV_DATA_IN

TV_CLK

TV_IR

LN_REG_ON

IIC_TU

FE1.2V

IF_AGC

IFD_OUT1

IFD_OUT2

SIF

IC8303

1.2V

SUB3.3V

A02

STB5.8V

IC8300

ATSC DEMODURATOR

SUB9V

IF_AGC

IFD1

DIGITAL DEMODULATOR

IFD2

IIC_TU

IIC_PRO

A09

IC5220

PANEL_LED

Q9970

IC5200

IC8304

TUNER5V

+5V

SUB_ON

D5422

D5423

+5V

SUB9V

PANEL_LED_ON

SUB5V

D9970

DTV12V

D5424

D5420

IC5601

+3.3V

DTV12V

D5425

D5421

SUB+3.3V

OVER VOLTAGE

D4831

D4833

IC5600

P17V

D4830

D4832

R2768

Q4770,71

SUB_ON

INV_PWM

INV_ON

BL_SOS

5.8V

A14

BACK LIGHT

PANEL

LCD PANEL

PANEL CONTROL

AVDD13.7V

DVDD2.5V

VOFF2-6V

VCON31V

VREF_1-12

LVDS DATA

IIC TCON

L/R

SUB3.3V

IC4802

D/A

IIC2

IIC TCON

PC-R

JK3304A

PC-G

HOT START (DAC_ENB)

PC-B

PC-V

PC-H

PANEL_VCC_ON

VDD25_EN

PANELPOWER SOS

(LED:3TIMES)

JK3300

AV2

AV3_V

(SIDE)

AV3_R

AV3_L

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