Sanyo 20XR1 Schematic

FILE NO.

SERVICE MANUAL						LCD-20XR1/AU
						PRODUCT CODE No.
LCD TV						1 682 340 53 : Australia

LCD-20XR1/AU

SPECIFICATIONS

Power supply: AC 100-240V 50/60Hz

Power Consumption: 130 W

Dimensions: 568(W) x 436(H) x 172(D)mm

Weight: 9 kg

Screen: 20’’

TV system & channel coverage:
System	VHF	UHF	CATV
PAL-B/G	2-12	21-69	X-Z+2, S1-S41

TV system: PAL BG, NTSC(AV)

Speaker: 8W, 8Ωx2

REFERENCE No. SM0915003

CONTENTS

Safety instructions………………………………………………………………………..… 1

Alignment instruction ……………………………….…….……………………………….…3

Trouble shooting ……………………………………………………….……………………5 Method of software upgrading ………………………………………….…….……………7

The unit working principle analysis……………………………….…………..…………. 10

Block diagram…………………………………..………………………………..………… 11

IC block diagram………………………………………………………………………..……12

Identification criteria for the bright spot and dark spot of the LCD screen………..…. 16 Wiring diagram ……………………………………………………………..……………... 17

Troubleshooting charts………………………………………………………………..…… 18

Schematic diagram ……………………………………………………………………………21

Exploded View ………………………………………………………………………………27 Parts list (Primary parts) ………………………………………………………………………28

SAFETYA INSTRUCTIONS

Attention: This service manual is only for service personnel to take reference with. Before servicing please read the following points carefully.

Safety instructions

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

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

2.2The 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.

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

2.4Never 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.

2.5If 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.

2.6Should 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.

2.7Do 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.

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

2.9As 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.

2.10There 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

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SAFETY INSTRUCTIONS

would be unable to work and no way to get it repaired.

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

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

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

3.3Be 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

3.4When 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.

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

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ALIGNMENT INSTRUCTION

Alignment instruction

1 Alignment equipment

PM5518 (video signal generator) K-7253 (VGA signal generator) CA210 (white balancer)

IF signal generator Signal generator Oscillograph

2 Alignment flow-chart

The alignment flow-chart is shown as Fig-1

Write memory N300 and N400

To produce main board and power supply board

Check power supply board and main adjustment

All testing

Connect with central signal source, then check each function of TV(Station missing, system identification, analog control etc.) , check the output of speaker

Input AV/S-video signal, and then check each function of AV/S-video

Input YPrPb signal and see if the display is normal under PC status and check various functions (analog control), line/field center etc.

Check the accessories and pack them in box

Fig-1 adjustment flow-chart

3 Unit adjustments

3.1Flash writing programs Written memory N300 and N400.

3.2Check power supply board

Turn off between power supply board and main board, after plug in power, testing X702 (pin1 and pin5) power supply board voltage to be 12v and 5v.

3.3 main board adjustment 3.3.1 IF amplifier adjustment

a. Turn off the J201, J202, J203, J204, J205 and J5, input 38MHz(PAL SYSTEM) and 45.75MHz(N

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ALIGNMENT INSTRUCTION

SYSTEM) for X210, input 9v(±0.05v) and 5v(±0.05v) to J202 and J203, adjust L210 to let x205 voltage to be 1.65v(±0.1v).

b.Solder to J201, J202, J203 and J5 3.3.2 AGC adjustment

Receiving 60dB signal of D-8 or A-7(N system), adjust RP201 to let 3v(±0.05v) of X204.

Input 100dB of antenna, the picture should not no-sync and distortion. Input 35-40db low signals, the picture should sync and the sound normal, but the color should not disappear.

3.3.3 white balance adjustment

a.Install the unit

b.Adjust to brightness for backlight

c.Access into the D-SUB channel input 16 level gray-scale 640 x 480@60Hz signal of VGA interface. Press , 2, 5, 8 and 0 buttons access factory menu, perform “reset ex-factory set” and auto color.

d.Exit factory menu, input gray(H)-8 signal, adjust picture mode to “nature”.

e.Enter factory menu fixed R-OFFSET1 to 0; adjust G-OFFSET1 and B-OFFSET1 to let second level to fit the table1.

f.Fixed R-GAIN to 200, adjust G-GAIN and B-GAIN to let seventh level to fit table1.

	Table1
Color temperature	9300K
X coordinate	0.285±0.008
Y coordinate	0.293±0.008

g.Repeat e step to f step, it must be measure a true value.

h.The unit without VGA interface of 20” (N system), you should be rework c step: enter VIDEO channel, input Gray(H)-16 for NTSC system of VIDEO interface, press , 2, 5, 8 and 0 buttons to access factory menu, perform “reset ex-factory set” and auto color.

4. Performance check a). TV Interfaces

Connect RF port to central signal source. Enter station search menu to auto station search. After system adjustment is correctly, check if there is any station missing and the output of earphone or loudspeaker and the picture is normal.

b). Interface of AV/S Terminals

input AV signal and switch to AV channel, see to the picture is normal, then input S terminal, check if it can auto identify is normal. Check if sound is normal.

c). VGA Interface

Input VGA signal (K7253 signal generator). Separately input the several types of VGA format signals as listed in Table 1. Then check if the picture and sound is normal. If there has been interference to the picture then press the auto set key on the remote control once again and check if the display is normal.

Table 1 Display Format of PC

Item	Resolution	Picture element clock	H-SYNC	V-SYNC	Remark
		(MHz)	(kHz)	(Hz)
1	640 x 480 @ 60	25.175	31.469	59.900

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ALIGNMENT INSTRUCTION AND TROUBLE SHOOTING

2	800 x 600 @ 60	40.000	37.879	60.317
3	1024 x 768 @ 60	65.000	48.363	60.004
4	1024 x 768 @ 70	75	56.48	70.07
5	1280 x 1024 @ 60	109.47	63.72	60

e). YPbPr Interface

Input YPbPr signal to YPbPr/YcbCr interface. Separately input the several types of YPbPr format signals: 480P/60Hz, 480P/59Hz; 720P/60Hz, 720P/59Hz; 1080i/60Hz, 1080i/59Hz; 1080p/60Hz, 1080p/59Hz and check if the picture and sound is normal.

5. Preset ex-works

In the status of TV enter the factory menu by pressing the factory key and then perform presetting. 6. Ex-works packing

Check accessories and then pack them in box.

Trouble shooting

Before servicing please check to find the possible causes of the troubles according to the table below.

1.Antenna (signal):

Picture is out of focus or jumping	z	Bad status in signal receiving
	z	Poor signal
	z Check if there are failures with the electrical connector or
		the antenna.
	z Check if the antenna is properly connected.
Fringe in picture	z	Check if the antenna is correctly oriented.
	z Maybe there is electric wave reflected from hilltop or
		building.
Picture is interfered by stripe	z	Possibly due to interference from automobile, train, high
shaped bright spots		voltage transmission line, neon lamp etc.
	z Maybe there is interference between antenna and power
		supply line. Please try to separate them in a longer
		distance.
	z Maybe the shielded-layer of signal wire is not connected
		properly to the connector.
There appear streaks or light color	z	Check if interfered by other equipment and if interfered
on the screen		possibly by the equipment like transmitting antenna,
		non-professional radio station and cellular phone.

2.TV set:

Symptoms	Possible cause
Unable to switch the power on	z Check to see if the power plug has been inserted
	properly into the socket.
No picture and sound	z Check to see if the power supply of liquid crystal TV
	has been switched on. ( as can be indicated by the
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TROUBLE SHOOTING

	red LED at the front of the TV set)
	z See if it’s receiving the signal that is transmitted from
	other source than the station
	z Check if it’s connected to the wrong terminal or if the
	input mode is correct.
	z Check if the signal cable connection between video
	source and the liquid crystal TV set is correct.
Deterioration of color phase or color	z Check if all the picture setups have been corrected.
tone
Screen position or size is not proper	z Check is the screen position and size is correctly set
	up.
Picture is twisted and deformed	z Check to see if the picture-frame ratio is properly set
	up.
Picture color changed or colorless	z Check the “Component” or “RGB” settings of the
	liquid crystal TV set and make proper adjustment
	according to the signal types.
Picture too bright and there is	z Check if the contrast setting is too high.
distortion in the brightest area	z Possibly the output quality of DVD broadcaster is set
	too high.
	z It maybe also due to improper terminal connection of
	the video signal in a certain position of the system.
Picture is whitish or too bright in the	z Check if the setting for the brightness is too high
darkest area of the picture	z Possibly the brightness grade of DVD player
	(broadcaster) is set too high.
No picture or signal produced from the	z Check if the cable is disconnected.
displayer if “XXX in search” appears.	z Check if it’s connected to the proper terminal or if the
	input mode is correct.
There appears an indication - “outside	z Check if the TV set can receive input signal. The
the receivable scope)	signal is not correctly identified and VGA format is
	beyond the specified scope.
Remote control cannot work properly	z Check if the batteries are installed in the reverse
	order.
	z Check if the battery is effective.
	z Check the distance or angle from the monitor.
	z Check if there is any obstruct between the remote
	control and the TV set.
	z Check if the remote control signalreceiving window
	is exposed to strong fluorescence.
No picture and sound, but only hash.	z Check if the antenna cable is correctly connected, or
	if it has received the video signal correctly.
Blur picture	z Check if the antenna cable is correctly connected.
	z Of if it has received the right video signal.
No sound	z Check if the “mute” audio frequency setting is
	selected.
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TROUBLE SHOOTING AND METHOD OF SOFTWARE UPGRADING

	Check if the sound volume is set to minimum.
	Make sure the earphone is not connected.
	Check if the cable connection is loose.
When playing VHS picture search	When being played or in pause VHS picture search
tape, there are lines at the top or	tape sometimes can’t provide stable picture, which
bottom of the picture.	may lead to incorrect display of the liquid crystal TV,
	In this case please press “auto” key on the remote
	control so as to enable the liquid crystal TV set to
	recheck the signal and then to display correct picture
	signal

Method of software upgrading

The Y# series models enable you to update software through the VGA interface. Hardware requirements: 1. One parallel cable with male end and female end;

2.One standard VGA cable;

3.The updating board especially for Y# main board.

The steps for updating software: 1. Install Gprobe 5.0:

The first: Double click the GProbe5[1].0.0.15_S0006-EXE-09A to install it:

According to the prompt of Windows and follow the steps one by one to finish the installation. The second: Double click the GPorbe5[1].0.0.15Update1_S0006-EXE-10A to install it:

According to the prompt of Windows and follow the steps one by one to finish the installation. 2. Copy the full directory of Isp_fastflash to anywhere

E.g. Take the root directory of C:\ as an example for the following explaination:

Copy the updating file *.hex to the directory of C:\ Isp_fastflash\

E.g. C:\ Isp_fastflash\20Y25.hex.

3. Open C:\ Isp_fastflash\Isp_parallel\ bat.txt as follows:

Properly set the path of RAMWrite "C:\isp_fastflash\Isp_parallel\TEMP_OBJECT\isptemp_ parallel.hex" and FastFlashWrite "C:\isp_fastflash\20y25.hex", save them and close.

4. Set the LCD to off. Connect the Y# updating board and PC with parallel cable.

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