Sanyo LCD- 22XR7SN Schematic

FILE NO.

SERVICE MANUAL LCD-22XR7SN

PRODUCT CODE No.

LCD TV

1 682 346 27:NTSC-M

REFERENCE No.:SM0915047

CONTENTS

Safety precautions………………………………………………………………………..… Alignment instructions …………………………….…….………………………………… Method of software upgrading…………………………………………………………….. Working principle analysis of the unit……………………………….………….…………. Block diagram…………………………………..………………………………….………… IC block diagram………………………………………………………………………..…… Wiring diagram ……………………………………………………………………………. Troubleshooting guide ………………………………………………………………..…… Schematic diagram………………………………………………………………………… APPENDIX-A: Assembly list APPENDIX-B: Exploded View

1 3 6 12 13 14 17 18 21

Attention: This service manual is only for service personnel to take reference with. Before

servicing please read the following points carefully.

Safety precautions

1. Instructions

Be sure to switch off the power supply before replacing or welding any components or inserting/plugging in connection wire Anti static measures to be taken (throughout the entire production process!): a) Do not touch here and there by hand at will; b) Be sure to use anti static electric iron; c) It’s a must for the welder to wear anti static gloves. Please refer to the detailed list before replacing components that have special safety requirements. Do not change the specs and type at will.

2. Points for attention in servicing of LCD

2.1 Screens are different from one model to another and therefore not interchangeable. Be sure to use the screen of the original model for replacement.

2.2 The operation voltage of LCD screen is 700-825V. Be sure to take proper measures in protecting yourself and the machine when testing the system in the course of normal operation or right after the power is switched off. Please do not touch the circuit or the metal part of the module that is in operation mode. Relevant operation is possible only one minute after the power is switched off.

2.3 Do not use any adapter that is not identical with the TV set. Otherwise it will cause fire or damage to the set.

2.4 Never operate the set or do any installation work in bad environment such as wet bathroom, laundry, kitchen, or nearby fire source, heating equipment and devices or exposure to sunlight etc. Otherwise bad effect will result.

2.5 If any foreign substance such as water, liquid, metal slices or other matters happens to fall into the module, be sure to cut the power off immediately and do not move anything on the module lest it should cause fire or electric shock due to contact with the high voltage or short circuit.

2.6 Should there be smoke, abnormal smell or sound from the module, please shut the power off at once. Likewise, if the screen is not working after the power is on or in the course of operation, the power must be cut off immediately and no more operation is allowed under the same condition.

2.7 Do not pull out or plug in the connection wire when the module is in operation or just after the power is off because in this case relatively high voltage still remains in the capacitor of the driving circuit. Please wait at least one minute before the pulling out or plugging in the connection wire.

2.8 When operating or installing LCD please don’t subject the LCD components to bending, twisting or extrusion, collision lest mishap should result.

2.9 As most of the circuitry in LCD TV set is composed of CMOS integrated circuits, it’s necessary to pay attention to anti statics. Before servicing LCD TV make sure to take anti static measure and ensure full grounding for all the parts that have to be grounded.

2.10 There are lots of connection wires between parts behind the LCD screen. When servicing or moving the set please take care not to touch or scratch them. Once they are damaged the screen

would be unable to work and no way to get it repaired. If the connection wires, connections or components fixed by the thermotropic glue need to disengage when service, please soak the thermotropic glue into the alcohol and then pull them out in case of dagmage.

2.11 Special care must be taken in transporting or handling it. Exquisite shock vibration may lead to breakage of screen glass or damage to driving circuit. Therefore it must be packed in a strong case before the transportation or handling.

2.12 For the storage make sure to put it in a place where the environment can be controlled so as to prevent the temperature and humidity from exceeding the limits as specified in the manual. For prolonged storage, it is necessary to house it in an anti-moisture bag and put them altogether in one place. The ambient conditions are tabulated as follows:

Temperature Scope for operation 0 ~ +50 oC

Scope for storage -20 ~ +60 oC

Humidity Scope for operation 20% ~ 85%

Scope for storage 10% ~ 90%

2.13 Display of a fixed picture for a long time may result in appearance of picture residue on the screen, as commonly called “ghost shadow”. The extent of the residual picture varies with the maker of LCD screen. This phenomenon doesn’t represent failure. This “ghost shadow” may remain in the picture for a period of time (several minutes). But when operating it please avoid displaying still picture in high brightness for a long time.

3. Points for attention during installation

3.1 The front panel of LCD screen is of glass. When installing it please make sure to put it in place.

3.2 For service or installation it’s necessary to use specified screw lest it should damage the screen.

3.3 Be sure to take anti dust measures. Any foreign substance that happens to fall down between the screen and the glass will affect the receiving and viewing effect

3.4 When dismantling or mounting the protective partition plate that is used for anti vibration and insulation please take care to keep it in intactness so as to avoid hidden trouble.

3.5 Be sure to protect the cabinet from damage or scratch during service, dismantling or mounting.

Alignment instructions

1. Test equipment

PM5518 (video signal generator) VG-849 (VGA and HDMI signal generator) CA210 (color analyzer)

2 Alignment flow-chart

The alignment flow-chart is shown as fig-1

Check DDC, HDCP KEY, FLASH and POWER control IC

Factory initialization setup

IF channel AFT voltage of TV and AGC voltage adjustment

ADC correction of VGA and YPbPr

White balance adjustment

Fig-1 adjustment flow-chart

3 Unit adjustments

Connect all the boards according to wiring diagram, connect with power and observe the display. Method for entering factory menu: press “INPUT”, “2”, “5”, ”8” and “0” in turn to enter factory menu; press “CH+” and “CH-” to select adjustment items and press “VOL+” and “VOL-” to adjust value items, press “MENU” repeatedly to exit. Method for software upgrading: When software upgrading please enter factory menu first, enter ISP item of OPTION, set ISP to 1 and you can begin to upgrade. After upgrade finished, it needs to set ISP back to 0. If the picture can’t display when upgrading, it needs to solder JB1 on the main board. Please unsolder JB1 again after upgrading.

3.1 Initialization Enter factory menu, select “OPTION”, “EEPROM” and “HOTEL OPTION” sub-menu, adjustment of items to see table1.

Table1 sub-menu adjustment

Items Preset Introduce

HOTEL 0 ON: HOTEL OPTION of factory menu is optional

OFF: HOTEL OPTION of factory menu is not optional

Performance check

Preset ex-factory

LOGO 1 ON: display LOGO in no signal or turn on

OFF: no LOGO display

ADC PRESCALE 02E Software will preset the data according the unit and the data can be adjusted when

needed.

SIF PRESCALE 02E Software will preset the data according the unit and the data can be adjusted when

needed.

BACK LIGHT FF Software will preset the data according the panel and the data can be adjusted

when needed.

ALL COLOR 1 1: white balance of each channel auto offset based on the HDMI white balance

0: white balance of each channel adjust the offset base separately

EEPROM-MEMORAY

RECALL

> EEPROM Initialization (operate when EEPROM data chaos)

3.2 Adjustment for AFT voltage and AGC voltage of IF channel in TV

3.2.1 IF AFT adjustment Enter the factory menu and set IF VCO to 1, or press “INPUT”, “2”, “5”,”8”, “1” to enter VCO

adjust mode, adjust L109 to value 2.5V of TP105 (B face), then set IF VCO to 0.

3.2.2 IF AGC adjustment

Input 60DB RF signal (184.25MHz for Chinese, 175.25MHz for America) to RF terminal, adjust RP101 to value 3V of TP102 (B face) and there should be no obvious snowy picture. Increase the signal to 90dBV and it should be display normally and no obvious noise.

3.3 White balance adjustment

3.3.1 white balance adjustment of HDMI

a. Input VG-848 signal from HDMI: TIMING854(800* 600/60Hz) and eighth level gray-scale

signal of PAT920. Use color analyzer CA210 to adjust white balance.

b. Enter submenu of COLOR TEMP. Select 9300k of color temperature

c. Fixed value of B OFF, adjust R OFF and G OFF, let the color coordinate of the second level be 285,293 and the brightness be about 3nit- 6nit. Fixed value of B GAIN, adjust R GAIN and G GAIN, let the color coordinate of seventh level be 285,293. Adjustment R OFF, G OFF, R GAIN and G GAIN repeatedly until the value of the two levels gray-scale be 285, 293.

3.3.2 VGA/YPBPR/AV white balance check and correction

a. Input VG-848 signal of VGA: TIMING854(800* 600/60Hz) (PATIERN:CROSS) and auto adjust to full screen, then input PAT948 black/white signal, enter factory menu ADC ADJ, select AUTOTUNE and wait for OK display. Input PAT920(8 gray levels), check if the white balance is normal, if not, enter COLOR TEMP menu, set ALL COLOR to 0 and fine adjust according the method of 3.3.1 c)

b. connect VG-848 signal of YPBPR to YPBPR terminal and input TIMING972(1080i/60HZ) 100% color bar of PAT976(include black/white bar), Enter submenu of ADC ADJ, Select AUTOTUNE and wait for OK display. Input PAT920(8 gray levels), check if the white balance is normal, if not, set ALL COLOR to 0 and fine adjust according the method of 3.3.1 c)

c. Input AV signal(PM5518, 8 gray levels, PAL for Chinese and NTSC for America) to VIDEO 1 terminal, check if the white balance is normal, if not, set ALL COLOR to 0 and fine adjust according the method of 3.3.1 c) Note: it can’t set back to 1 once ALL COLOR changes to 0.

4 Performance check

4.1 TV function Enter searching menu → auto search, connect RF-TV terminal with central signal source and check if the picture is normal, if there are channels be skipped. Check CCD and V-CHIP function (for America).

4.2 AV/S, YPbPr terminals Input AV/S, YPbPr/YCbCr HD signal, check if it is normal.

4.3 VGA terminal Insert VGA terminal, input VGA format signal of 640X480@60 Hz and check if the display is normal.

4.4 HDMI terminal Insert HDMI terminal, input signal of 640 X 480@60 Hz signal and check if the display is normal and the HDCP is normal.

4.5 check sound channel Check the speaker and headphone of each channel.

4.6 other function check Check the turn on/turn off timer, asleep timer, picture/sound mode, OSD, freeze/mute, stereo/SAP(for America), magic picture, etc.

4.7 presetting before ex-factory

Item Setting Item Setting Item Setting

PICTURE MODE NAUTRAL

AUDIO MODE DK

SOUND MODE NEWS HALFTONE 50

NR WEAK DURATION 15 ANTENNA CATV

ZOOM FULL

OSD language

English /

Chinese

VGA/HDMI

color temperature

STANDARD

Method of software upgrading

1. The tools and software demanded

1) Please confirm that PC has the software of ISP_TOOL and install the parallel interface drive program Port95nt.

2) ISP_TOOL icon is bellow:

3) One parallel cable (25 pins) and one VGA cable (15 pins), the parallel cable connects the PC and the upgrade instrument, the VGA cable connects the TV and the upgrade instrument.

2. The steps for upgrading software

1) Please confirm that the connection wires and the upgrade instrument are connected well before the software written and then power on the TV.

2) Double click the icon ISP_TOOL to open it:

3) Press “Connect“ to connect TV, if the connection is done successfully as shown below, then press “enter”.

Note: if it appears error, check the connection wires and check if ISP item of the factory menu is set to 1, if not, please set it to 1.

4) After connection is done, it needs to read the Binary document. Press “Read” as shown below:

5) Search the document needed to write in the “Read” check box.

Select

6) Select the document then the window will appear as shown below:

7) Press “Auto” to select the writing function.

Select the items shown in the picture above: (a) Read File

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