SERVICE MANUAL - rtellason.comrtellason.com/manuals/TV-8888-69.pdf · COLOUR TELEVISION SERVICE MANUAL ... In the Schematic Diagram and Replacement Parts List. It is essential that

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F6B

COLOUR TELEVISION

SERVICE MANUAL

Features 51CM pure flat picture tube CCD function 181 program presetting and memory

Parental control

Inner DVD

Inner VCR

AV stereo and MTS

Models TDVCF2016

TV-8888-69

http://www.fineprint.com.cn

Color Television Model：20S62(TDVCF2016)

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CONTENTS

1 Product Code illumination and Series Introduction --------------------2

2 Features --------------------------------------------------------------------------------3

3 Specifications-------------------------------------------------------------------------4

4 Safety Precautions-------------------------------------------------------------------5

5 Warning and Cautions--------------------------------------------------------------6

6 Net dimension------------------------------------------------------------------------12

7 Parts and Functions----------------------------------------------------------------13

8 Remote Controller Functions----------------------------------------------------14

9 Maintenance Service --------------------------------------------------------------16

10 Circuit Diagram-----------------------------------------------------------------------22

11 Circuit Explanation------------------------------------------------------------------23

12 Adjustment-----------------------------------------------------------------------------28



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1. Product Code illumination and Series Introduction

20 S 62

CRT size(unit:inch)

VCR/DVD/TV combine

Model series of aspect number


2. Features

Color Television Model： 20S62(TDVCF2016)

MODEL:20S62 MODEL:20

S62 N O.

ITEM

FUNCTION

America

NO

.

ITEM

FUNCTION

America 1 Main IC LA76834 24 Digital curtain ×

2 CRT Pure flat 25 Slow fading on & off ×

3 Color system NTSC 26 Semitransparent menu √

4 Audio system M 27 No-flashing channel changing ×

5 NO.of channels 181 28 ZOOM ×

6 OSD language

English/French/Sp anish

29 16:9 mode

×

7

PICTURE

Multi-picture modes 1 30 Games ×

8 AV stereo √ 31 Calendar ×

9 Super woofer × 32 Child-lock ×

10 Surrounding sound × 33 Multi-functional lock ×

11 Treble/bass boost √ 34 No-picture listening ×

12 Left/right balancer √ 35 Background light ×

13 NICAM × 36 Auto-timer on √

14 Multi-audio modes × 37 CCD √

15 Tone adjuster × 38

SOFTWA RE

V-CHIP √

16 MTS/SAP √ 39 NO. of built-in speakers 2

17

AUDIO

Auto-volume leveling × 40 Audio output power(W) 2*1.5W

18 AV input back 1,front 1 41 Total power input（ W） 100W

19 AV output √ 42 Voltage range（ V） 120V

20 DVD terminal × 43 Power frequency（ Hz） 60HZ

21 S-video jack × 44 Time of sleep timer(MINS) 120

22 Headphone socket front 45 Net weight(KG) 25

23

JACK

SCART socket × 46 Gross weight(KG) 27.5

*

Inner DVD

inner DVD function √

47 Net dimension(MM)

570*480*51 0

*

inner VCR function

√

48 Packaged dimension(MM)

640*550*56 0

HiFi √ 49 Quantity for 20' container ×

Inner VCR SP/EP √ 50 Quantity for 40' container ×

51

PARAME TER

Quantity for 40' high container ×

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3. Specifications

l POWER SUPPLY: AC 120V, 60 Hz

l Tuning system: FS tuner

l IF: 45.75MHz

l Power consumption: 100W

l Antenna input impedance: 75Ω

l Receiving system:

a) Color system: NTSC

b) Broadcast TV system: M

l Language displayed: English/French/Spanish

l Video input: 1.0VP-P (75Ω)

l Audio input: 436m Vrms (40KΩ)

l VCR system: NTSC, HiFi, SP/EP;

l DVD district mode: 1;

Specifications



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4.Safety Precautions

IMPORTANT SAFETY NOTICE Many electrical identify these parts and mechanical parts in this chassis have special safety-related characteristics! In the Schematic Diagram and Replacement Parts List.

It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent X-RADIATION, Shock, Fire, or other Hazards.

Do not modify the original design without permission of the manufacturer.

General Guidance

An Isolation Transformer should always be used during the servicing of a receiver whose chassis is not isolated from the AC power line. Use a transformer of adequate power rating as this protects the technician from accidents that might result in personal injury caused by electrical shocks.

It will also protect the receiver and it’s components from being damaged by accidental shorts of the circuitry that might be inadvertently introduced during the service operation.

If any fuse (or Fusible Resistor) in this TV receiver is blown, replace it with a specified one.

When replacing a high wattage resistor (Oxide Metal Film Resistor, over 1W), keep the resistor 10mm away from PCB.

Keep wires away from high voltage or high temperature parts.

Due to the high vacuum and large surface area of the picture tube, extreme care should be taken in handling the Picture Tube. Do not lift the Picture Tube by its Neck.

X-RAY Radiation

Warning:

The source of X-RAY RADIATION in this TV receiver is the High Voltage Section and the Picture Tube.

For continued X-RAY RADIATION protection, the replacement tube must be of the same type as specified in the Replacement Parts List.

Before returning the receiver to the customer,

Always perform an AC leakage current check on the exposed metallic parts of the cabinet, such as antennas, terminals, etc., to make sure that the set is safe to operate without any danger of electrical shock.

Safety Precautions



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5. Warning and Cautions 1. When you clean the TV set, please pull out the power plug from AC outlet. Don't clean the cabinet and the screen with benzene, petrol and other chemicals.

4. To prevent the TV set from firing and electric shock, don'tmake the TV set rain or moisture.

2. In order to prolong the using life of the TV set, please place it on a ventilated place.

5. Don't open the back cover, otherwise it is possible to damage the components in the TV set and harm you.

3. Don't place the TV set in the sunshine or near heat source.

6. When the TV set isn't going to be used for long time or it is in thunder and lightening, please pull out the plug from AC outlet and the antenna plug from the cover of the TV set.

Explanation on the display tube

Generally, it is not needed to clean the tube surface. However, if necessary,its surface can be cleaned with a dry cotton cloth after cutting off the power.Don't use any cleanser. If using hard cloth, the tube surface will be damaged.

CAUTION: Before servicing receivers covered by this service manual and its supplements and addenda, read and follow the SAFETY PRECAUTIONS. NOTE: If unforeseen circumstances create conflict between the following servicing precautions and any of the safety precautions, always follow the safety precautions.



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Remember: Safety First.

General Servicing Precautions

1. Always unplug the receiver AC power cord from the AC power source before:

a. Removing or reinstalling any component, circuit board module or any other assembly of the receiver.

b. Disconnecting or reconnecting any receiver electrical plug or other electrical connection.

c. Connecting a test substitute in parallel with an electrolytic capacitor in the receiver.

CAUTION: A wrong substitution part or incorrect installation polarity of electrolytic capacitors may result in an explosion hazard.

d. Discharging the picture tube anode.

2. Test high voltage only by measuring it with an appropriate high voltage meter or other voltage-measuring device (DVM, FETVOM, etc.) equipped with a suitable high voltage probe. Do not test high voltage by “drawing an arc”.

3. Discharge the picture tube anode only by (a) first connecting one end of an insulated clip lead to the degaussing or kine aquadag grounding system shield at the point where the picture tube socket ground lead is connected, and then (b) touch the other end of the insulated clip lead to the picture tube anode button, using an insulating handle to avoid personal contact with high voltage.

4. Do not spray chemicals on or near this receiver or any of its assemblies.

5. Unless specified otherwise in this service manual, clean electrical contacts only by applying the following mixture to the contacts with a pipe cleaner, cotton-tipped stick or comparable nonabrasive applicator; 10% (by volume) Acetone and 90% (by volume) isopropyl alcohol (90%-99% strength)

CAUTION: This is a flammable mixture.

Unless specified otherwise in this service manual, lubrication of contacts is not required.

6. Do not defeat any plug / socket B+ voltage interlocks with which receivers covered by this service manual might be equipped.

7. Do not apply AC power to this instrument and/or any of its electrical assemblies unless all solid-state device heat sinks are correctly installed.

8. Always connect the test receiver ground lead to the receiver chassis ground before connecting the test receiver positive lead.

Always remove the test receiver ground lead last.

9. Use with this receiver only the test fixtures specified in this service manual.

CAUTION: Do not connect the test fixture ground strap to any heat sink in this receiver.

Electrostatic ally Sensitive (ES) Devices



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Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components are usually called Electrostatic ally 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 static electricity.

1. Immediately before handling any semiconductor component or semiconductor- equipped assembly, drain off any electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging wrist strap device, which should be removed to prevent potential shock 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 type folder removal device. Some solder removal devices not classified as “anti-static” can generate electrical charges 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 even some normally harmless motions such as mutual brushing of your clothes’ fabric or lifting of your foot from a carpeted floor might generate static electricity sufficient to damage an ES device.)

General Soldering Guidelines

1. Use a grounded-tip, low-wattage soldering iron and appropriate tip size and shape that will maintain tip temperature within the range of 500 oF to 600 oF.

2. Use an appropriate gauge of RMA resin-core solder composed of 60 parts tin/40 parts lead.

3. Keep the soldering iron tip clean and well tinned.

4. Thoroughly clean the surfaces to be soldered. Use a mall wire bristle (0.5 inch, or 1.25cm) brush with a metal handle. Do not use freon-propelled spay-on cleaners.



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5. Use the following unsoldering technique

a. Allow the soldering iron tip to reach normal temperature. (500 o F to 600o F)

b. Heating the component lead until the solder melts.

c. Quickly draw the melted solder with an anti-static, suction-type solder removal device with solder braid.

CAUTION: Work quickly to avoid overheating the circuit board printed foil.

6. Use the following unsoldering technique

a. Allow the soldering iron tip to reach normal temperature. (500 o F to 600o F)

b. First, hold the soldering iron tip and solder the strand against the component lead until the solder melts.

c. Quickly move the soldering iron tip to the junction of the component lead and the printed circuit foil, and hold it there only until the solder flows onto and around both the component lead and the foil.

CAUTION: Work quickly to avoid overheating the circuit board printed foil.

d. Closely inspect the solder area and remove any excess or splashed solder with a small wire-bristle brush.

Remove /Replacement

Some chassis circuit boards have slotted holes (oblong) through which the IC leads are inserted and then bent flat against the circuit foil. When holes are of slotted type, the following technique should be used to remove and replace the IC. When working with boards using the familiar round hole, use the standard technique as outlined.

Removal

Desolder and straighten each IC lead in one operation by gently prying up on the lead with the soldering iron tip as the solder melts.

Draw away the melted solder with an anti-static suction-type solder removal device (or with solder braid) before removing the IC.

Replacement

Carefully insert the replacement IC in the circuit board.

Carefully bend each IC lead against the circuit foil pad and solder it.

Clean the soldered areas with a small wire-bristle brush. (It is not necessary to reapply acrylic coating to the areas).

“Small-Signal” Discrete Transistor Removal/Replacement

Remove the defective transistor by clipping its leads as close as possible to the component body.

Bend into a “U” shape the end of each of three leads remaining on the circuit board.



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Bend into a “U” shape the replacement transistor leads.

Connect the replacement transistor leads to the corresponding leads extending from the circuit board and crimp the “U” with long nose pliers to insure metal to metal contact then solder each connection.

Power Output, Transistor Device Removal/Replacement

Heat and remove all solder from around the transistor leads.

Remove the heat sink mounting screw (if so equipped).

Carefully remove the transistor from the heat sink of the circuit board.

Insert new transistor in the circuit board.

Solder each transistor lead, and clip off excess lead.

Replace heat sink.

Diode Removal/Replacement

Remove defective diode by clipping its leads as close as possible to diode body.

Bend the two remaining leads perpendicularly to the circuit board.

Observing diode polarity, wrap each lead of the new diode round the corresponding lead on the circuit board.

Securely crimp each connection and solder it.

Inspect (on the circuit board copper side) the solder joints of the two “original” leads. If they are not shiny, reheat them and if necessary, apply additional solder.

Fuse and Conventional Resistor Removal/Replacement

1. Clip each fuse or resistor lead at top of the circuit board hollow stake.

2. Securely crimp the leads of replacement component around notch at stake top.

3. Solder the connections

CAUTION: Maintain original spacing between the replaced component and adjacent components and the circuit board to prevent excessive component temperatures.

Circuit Board Foil Repair

Excessive heat applied to the copper foil of any printed circuit board will weaken the adhesive that bonds foil to the circuit board causing the foil to separate from or “lift-off” the board. The following guidelines and procedures should be followed whenever this condition is encountered.

At IC Connections

To repair a defective copper pattern at IC connections use the following procedure to install a jumper wire on the copper pattern side of the circuit board. (Use this technique only on IC connections).



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1. Carefully remove the damaged copper pattern with a sharp knife. (Remove only as much

copper as absolutely necessary).

2. Carefully scratch away the solder resist and acrylic coating (if used) from the end of the remaining copper pattern.

3. Bend a small “U” in one end of a small gauge jumper wire and carefully crimp it around the IC pin. Solder the IC connection.

4. Route the jumper wire along the path of the out-away copper pattern and let it overlap the previously scraped end of the good copper pattern. Solder the overlapped area and clip off any excess jumper wire.

At other connections

Use the following technique to repair the defective copper pattern at connections other than IC Pins. This technique involves the installation of a jumper wire on the component side of the circuit board.

1. Remove the defective copper pattern with a sharp knife.

Remove at least 1/4 inch of copper, to insure that a hazardous condition will not exist if the jumper wire opens.

2. Trace along the copper pattern from both sides of the pattern break and locate the nearest component that is directly connected to the affected copper pattern.

3. Connect insulated 20-gauge jumper wire from the lead of the nearest component on one side of the pattern break to the lead of the nearest component on the other side.

Carefully crimp and solder the connections.

CAUTION: Be sure the insulated jumper wire is dressed so that it does not touch components or sharp edges.



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5. Net dimension

The Net dimension(MM) is 570*480*510.



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7. Parts and Functions

(1). Front panel of the TV set

(2). Rear panel of the TV set



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8. Remote Controller Functions



9. Maintenance Service and Trouble shooting A. Principle integrated circuits

A1.20S62 color TV set composed of the following sections

position specification model supplier

I801 power IC STR-W6735 SanKen

T804 power switching transformer BCK-08A6F-3 Ningbo Lishunda

T401 FBT JF0501-19810B Wuxi Jingshi I808/I806 5V IC KIA278R05 /

I807 12V IC KIA78S12P KEC

I805 9V IC KIA78R09 /

I804 5V IC L7805CV /

Q401 audion for H deflection 2SD2499 Toshiba

I301 Vertical deflection IC LA78040 Sanyo

I803 2.5V IC KA431AZTA /

I802 phototransistor PC817B Sharp

I501 CVBS decoding and TV IC LA76834NM Sanyo

I201 VCR decoding IC LA71207M Sanyo

IH01 HiFi and MTS IC LA72670BM Sanyo

I701 CPU IC M37762XXX CASTI

IS01 switching MM1492 MITSUMI

I601 sound process IC TDA7449 ST

I502 comb filter IC TDA9183P Philips

I602 sound amplifier LA4635A Sanyo

I703 memory IC AT24C08 Microchip

I702 audion KIA7033P

DVD-76834 software DS-C011B-A DESAY VCR NTSC-DECK DAEWOO

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11. Circuit Explanation


1. Definition and voltage of every pin on every IC.

Measure condition: picture is Philips color round;

Brightness and contrast is 42;

Sound is music;

Volume is 20;

Use FLUKE 17B, DC voltage.

This is tentative version.

(1) power IC: STR-W6735 Pin definition Voltage(V) remark

1 Drain 129

2 NC / /

3 S/GND 0.066 Source/Grond

4 VCC 15

5

SS/OLP

0.145 soft start time set up and overload protection

6 FB 1.310 Feedback terminal

7

OCP/BD

1.048 over current protection and

bottom detection terminal

(2) Vertical deflection IC: LA78040(or LA78041) Pin definition Voltage(V) remark

1 input 2.27 Vertical signal from LA76834

2 VCC 25

3 pump up 2.18

4 GND 0

5 output 13.7

6 out VCC 25.3

7 reference 2.28 Reference voltage

(3) Phototransistor: PC817B Pin definition Voltage(V) remark

1 input VCC 9.4 Sampling from +B voltage

2 input 8.4 Sampling from +B voltage

3 output 7.5 Provide feedback to power

4 output VCC 14.9 Provide feedback to power

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(4) CVBS decoding and TV IC: LA76834

Pin definition Voltage(V) remark

1 F.GND 0

2 F.GND 0

3 F.GND 0

4 F.GND 0

5 IF GND 0

6 IF VCC 4.82

7 FM Filter 1.906

8 AFT Output 2.158 To Pin 9 of M37760

9 Bus Data 3.32 The first bus

10 Bus Clock 3.60 The first bus

11 ABL 3.506 ABL from FBT

12 OSD Red input 1.35 OSD from P64 of M37760

13 OSD Green input 1.365 OSD from P63 of M37760

14 OSD Blue input 1.34 OSD from P62 of M37760

15 OSD Blanking input 0.005 OSD from P61 of M37760

16 RGB VCC 8.17 SW+9V

17 Red output 3.536 To CRT board

18 Green output 3.47 To CRT board

19 Blue output 3.642 To CRT board

20 V Size Comp input 3.88

21 F.GND 0

22 F.GND 0

23 F.GND 0

24 F.GND 0

25 E/W output 1.166

26 Vertical output 2.395

27 V Ramp ALC Filter 2.67

28 Horizontal/BUS VCC 5.22 Come from SW+9V

29 Horizontal AFC Filter 2.684

30 Horizontal output 0.62

31 H.GND 0

32 CPU Reset VCC input 0.013 Not used

33 Flyback pulse input 0.803 FBP from FBT

34 H VCO I ref 1.725

35 CPU Reset output 0.013 Not used

36 Vertical SYNC 4.87 Come from P59 of M37760

37 Horizontal SYNC 4.15 Come from P58 of M37760

38 OSD contrast 4.52

39 H.GND 0

40

X-RAY

0.017 receive OCP signal from power board

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41 F.GND 0

42 F.GND 0

43 F.GND 0

44 fsc(3.58MHz) output 2.397 Not used

45 Chroma APC Filter 3.4

46 Clamp Filter 1.81 Y Filter

47 3.58MHz Crystal input 2.6

48 NC 0 Connect to GND

49 Selected Video Output 2.77 Not used

50 Video/Chroma/Vertical GND 0


52 External Video input(Y in) 2.94

53 Video/Vertical VCC 4.78

54 Internal Video Input(S-C IN) 2.49 Not used

55

DC reset&black level detector

2.51 DC reset filter and black stretch

56

Video output

2.48 Output signal to P43 of MM1492


58 FLL Filter 3.76 VCO filter

59 VCO Coil 2 4.13

60 VCO Coil 1 4.13

61 F.GND 0

62 F.GND 0

63 F.GND 0

64 F.GND 0

65 APC Filter 2.32 PIF APC filter

66 Ext. Audio input 2.15 Not used

67 SIF output 1.92

68 SIF APC Filter 2.38

69 SIF input 3.08 Not used




73 audio output 2.23 Not used


75

FM output

2.34 To P42 and P44 of MM1492 TV mono sound output

76 PIF AGC filter 2.5

77 RF AGC output 1.2 To tuner

78 PIF input 2 2.84 From SAWF

79 PIF input 1 2.84 From SAWF

80 IF GND 0

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(5) sound process IC: TDA7449


1 CREF 4.51

2 Vs 8.98 From SW+9V

3 PGND 0

4 ROUT 3.79

5 LOUT 3.79

6 R_IN2 4.5 Not used

7 R_LN1 4.5

8 L_IN1 4.5

9 L_IN2 4.5 Not used

10 MUXOUT(L) 4.53

11 MUXOUT(R) 4.53

12 BIN(R) 0

13 BOUT(R) 0

14 BOUT(L) 0

15 BIN(L) 0

16 TREBLE(L) 0

17 TREBLE(R) 0

18 DIG_GND 0

19 SCL 4.45 The second bus

20 SDA 4.28 The second bus

(6) sound amplifier IC: LA4635A


1 DC(Ripple Filter) 6.9

2 IN1(L) 1.58

3 GND 0

4 IN2(R) 1.58

5 STBY 1.01

6 P.P(Popping Noise Eliminator) 9.8

7 VCC 13.75

8 OUT2(R) 6.75

9 NC 0

10 PWR GND 0

11 NC 0

12 OUT1(L) 6.75

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(7) VCR decoding IC: LA71207


1 VREF 2.3V 2.3

2 audio line amp PB in 2.3

3 SP 2.3

4 LP 2.3

5 EQ AMP 2.3

6

PB.EE（ A.HEAD PLAYBACK）

2.3

Receive normal sound signal from VCR and send it to P6 of LA71207M

7 REC:LP,EP 0.1

8 REC:PB,EP 2.3

9 REC AMP 2.3

10 MUTE 2.3 Connect to the P4 of LA72670

11 AUTO BIAS 0.1

12 phase EQ f0 CTL 1

13 phase EQ Q CTL 0.8

14 PB ENVE 1.9 To adjustment board

15 FM AGC filter 1.4

16 Y-GND 0

17 5V 4

18 main emphasis filter 2.4

19 S DET 0

20 emphs\asis filter 2.5

21 main de emphasis out 1.8

22 clamp in 3.1

23 Y-Vcc 4.8 SW +5V

24 QV.SYNC 0 Come from P13 of M37760

25 NC 0.3

26

Cvin

1.9

Send CVBS signal of VCR to P13 of MM1492 and to P56 of M37760

27 AGC TC2 1.5

28 NC 2.2 Not used

29 AGC TC1/BALANCER 2.3

30 NC 2.2

31 REG 4V 4.1

32

CVBS in

2.3

Receive CVBS signal from P23 of MM1492

33 VCP FILTER 2.9

34 CLAMP 3

35 VCA 3.1

36 CCD DRIVE 2.2

37 CLAMP 2.6

38 GND 0

39 CCD OUT 1.5

40 GND 0

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41 PLL 0.8

42 PLL 2.2

43 NC 0

44 CCD VCC 4.86 SW +5V

45 VCC 4.9 CPU +5V

46 NC 2.4

47 SLD 3.4

48 320FH VCO 3.5

49 3.58M crystal input 3.9

50 VX01 2.5

51 REC APC 2.1

52 C Vcc 4.8 SW +5V

53 SCL 4.1 The first bus

54 SDA 3.9 The first bus

55 VCR CS 0.3 Connect to P73 of M37760

56 C GND 0

57 C_ROT(rotary) 0 Connect to P15 of M37760

58 HA.SW 0 Connect to P16 of M37760

59 ENVE DET 0.8 Connect to P10 of M37760

60 ENVE COM 4.8 Connect to P17 of M37760

61 killer filter 1.9

62 head amp GND 0

63 CHROMA DET 2.7

64 ACC DET 1.6

65 SP_L 0.7

66 SP_COM 0.7

67 SP_R 0.7

68 HA_VCC 4.88 SW +5V

69 REC CURRENT AJUST OUTPUT 4.87

70 REC CURRENT ADJUST INPUT 0.05

71 HA_GND 0

72 EP_L 1.8

73 EP_COM 1.8

74 EP_R 1.8

75 A_GND 0

76 AUDIO IN-1 2.2 Connect to P6 of LA72670

77 A_VCC 4.9 SW +5V

78 NC 2.2

79 ALC DET 1.1

80 NC 2.2

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(8) switching of CVBS signal and sound signal IC: MM1492


1 V1-V 4.86 Front AV VIDEO input

2 V1-L 0.039 Front AV AUDIO L input

3 V1-Y 4.9 Not used

4 V1-R 4.3 Front AV AUDIO R input

5 V1-C 4.85 Not used

6 S1 0.023 Not used

7 V2-V 4.9 DVD CVBS signal input

8 V2-L 4.33 DVD AUDIO L input

9 V2-Y 4.89 Not used

10 V2-R 4.33 DVD AUDIO R input

11 V2-C 4.85 Not used

12 S2 0 Not used

13 V3-V 5.33 VCR CVBS signal input

14 V3-L 4.32 VCR AUDIO L input

15 V3-R 4.32 VCR AUDIO R input

16 STV-V 4.86 Rear AV VIDEO input

17 STV-L 0 Rear AV AUDIO L input

18 STV-R 4.33 Rear AV AUDIO R input

19 Yin2 4.9 Not used

20 ADR 0 GND

21 Cin2 4.84 Not used

22 GND 0 GND

23 Vout2 5.21 CVBS output to VCR

24 Rout2 4.2 AUDIO R output to VCR

25 Cout2 3.4 Not used

26 Lout2 4.17 AUDIO L output to VCR

27 Yout2 3.4 Not used

28 GND 0



31 MUTE 0 Not used

32 Cin1 4.84 Not used

33 GND 0

34 Yin1 4.89 Not used

35 Rout1 4.17 AUDIO R output to TDA7449

36 Lout1 4.16 AUDIO L output to TDA7449

37 Vout1 5.2 CVBS output to LA76834

38 BIAS 4.39

39 Yout1 3.4 Not used

40 Vcc 8.92 SW +9V

41 Cout1 3.41 Not used

42 MTV-R 4.33 TV AUDIO signal input

43 MTV-V 5.34 TV CVBS signal input

44 MTV-L 4.34 TV AUDIO signal input

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Color Television Model： 20S62(TDVCF2016) (9) Hi-Fi decoding and MTS IC: LA72670


1

Line mute terminal（ L)

0 Send VCR AUDIO L signal to P14 of MM1492

2 NC 2.55 Not used

3 VCC 8.86 SW +9V

4 MUTE 2.5

5 VCC 4.86 SW +5V

6 normal output terminal 1.91

7 VCR/SW(SW L IN) 0.1 Connect to P26 of MM1492

8 RF ALC detection 3

9 NC 0.4

10 GND 0

11 NC 0.4

12 NC 2.5

13 input changeover switch output(L) 1.9

14 HI-FI input terminal(L) 2.5

15 VCC 4.86 SW +5V

16 VREF 2.5

17 GND 0

18 NR waiting DET terminal(L) 0.1

19 NR waiting filter terminal1(L) 2.5

20 NR waiting filter terminal1(R) 2.5

21 CCA reference terminal(L) 2.5

22 NR emphasis terminal(L) 2.5

23 HI-FI(H) 0.02 Send signal to P8 of M37760

24 A-R(normal sound signal from VCR) 2.1 Receive signal from P201

25 PRE.GND 0

26 A-COM(normal sound signal from VCR) 2.1 Receive signal from P201

27 A-L(normal sound signal from VCR) 2.1 Receive signal from P201

28 COMP 0

29 SAP DET 2.7

30 NOISE DET 0

31 NC 2.5

32 VCC 5V 4.85 SW +5V

33 PB AMP output 2.5

34 PB FM input terminal 2.5

35 GND 0

36 LOGIC 4.86 VCC(SW +5V)



39 HOLD PULSE(A.H.SW) 0 Connect to P19 of M37760

40 ST/SAP/MONO SW 1 Connect to P5 of M37760

41 R-CH PNR 2.5

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42 R-CH PNR 2.5

43 R-CH PNR 2.6

44 R-CH PNR 2.6

45 R-CH PNR/NR waiting DET terminal(L) 0.2

46 VCC 4.86 SW +5V

47 HI-FI input terminal(R) 2.5

48 input changeover switch output(L) 1.9

49 A.MUTE 0 Connect to P26 of M37760

50 A.GND 0

51 PLL 2.1

52 Ripple filter 1.2

53 stereo PLL filter 3.8

54 9V power supply for MTS 8.86 SW +9V

55 pilot canceller filter 3.8

56 FM filter 2.1

57 SIF2 2.2

58 VREF 4.5

59 filter auto adj 2.4

60 pilot det filter 3.8

61 PC_DC_MO 3.2

62 PCDCOUT 3.8

63 PCDCIN 3.8

64 PCDBXIN 2.5

65 MAIN V/I CONVERT 3.8

66 SPECTRAL DET 4.1

67 SPE DET V/I CONVERT 3.9

68 WIDE BAND DET 3.9

69 Video SW 0.1 Connect to P18 of M37760

70 GND 0

71 NC 0.1 Not used

72 WID DEP V/I CONVERT 3.8 Dbx dec

73 NC 0.1 Not used

74 NC 2.5 Not used

75 PCDCOSPE 3.8

76 PC_OUT_DBX 3.2

77

Line mute terminal（ R)

0

Send VCR AUDIO R signal to P15 of MM1492

78 line Out(R)terminal 4.3

79 A.GND 0

80 line Out(L) terminal 4.3

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(10) CPU of the whole set: M37760(M37762 after MASK)


1 KEY1 4.84 VCR key

2 KEY2 4.84 DVD key

3 CNC 0.023 Not used

4 PATH ADJ. 4.69 Connect to adjustment small board

5 STEREO/SAP/MONO 0.973 Connect to P40 of LA72670

6 C-DECK(H)OPTION 0 Connect to GND

7 POWER FAIL(L) 4.63

8 HI-FI(H) 0.030

9 AFT 2.170

10 ENVE DET. 0 Connect to P59 of LA71207

11 NC 0 Not used

12 NC 0 Not used

13 QV SYNC 0

14 REMDCON IN 4.83

15 C.ROTARY 0.016

16 HA .SW 0.016

17 ENVE COMP 4.84

18 VIDEO SW 0.016

19 A.H.SW 0.016

20 REC(H) 0

21 NC 0

22 PWR OFF(H) 0.016

23 CAP F/R 0

24 NC 0.015

25 NC 0.015

26 A MUTE(H) 0.015 Connect to P58 of LA71207

27 CAP.I.LIM 1.506

28 T.R/REC LED 0.015

29 ST-BY LED 0.015

30 CRT_ON(H) 4.75

31 PWR ON(H) 4.78

32 RLY-ON(H) 0.014

33 DVD_ON(H) 4.78

34 RESET(L) 4.78

35 COMB OPTION 0.007 Connect to GND

36 NC 0.004

37 VCC 4.79 CPU +5V

38 SYSCON IN 2.153 14.3181MHz

39 SYSCON OUT 2.183 14.3181MHz

40 GND 0.007

41 NC 0.005

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42 NC 0.012

43 CLK SEL 4.84

44 OSD IN 2.290

45 OSD OUT 2.289

46 NUB 0.007 Connect to GND

47 NC 1.390

48 NC 0.004

49 OSD GND 0.007

50 NC 2.664

51 NC 0.031

52 NC 0.040

53 OSD VCC 4.79 CPU +5V

54 HLF 1.971

55 V HOLD 1.501

56 Cvin(EDS) 2.007 Come from P26 of LA71207

57 NUA 0.007 Connect to GND

58 HOR.SYNC 4.16

59 VER.SYNC 4.89

60 OSD BOX 0.015

61 OSD BLANKING 0

62 OSD B 0

63 OSD G 0.015

64 OSD R 0.016

65 S.OUT(DVD) 4.74

66 S.IN(DVD) 5.20

67 S.CLK(DVD) 0

68 SDA_2 4.25 The second bus

69 SPK MUTE(H) 0.016

70 SCL_2 4.41 The second bus

71 V CLK 3.58 The first bus

72 V DATA 3.321 The first bus

73 VCR CS 0.381 Connect to P55 of LA71207

74 LM CTL 0 Connect to P204 of VCR

75 NC 0.015

76 DRUM PWM 0.015 Connect to P204 of VCR

77 CAPS PWM 0.014 Connect to P204 of VCR

78 DVD CS 5.19

79 RLS 4.74 Connect to S201

80 RLT 4.72 Connect to S202

81 NC 0.015

82 CAM C 4.74

83 CAM B 4.74

84 CAM A 4.74

85 0.011

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86 REC.SAFE.SW 4.84 Connect to S203

87 CAP FG 2.42 Connect to P204 of VCR

88 AMP GND 0.011

89 DRUM FG 0.011

90 DRUM PG/FG 0 Connect to P204 of VCR

91 AMP REF.OUT 2.429

92 AMP REF.IN 2.425

93 C 0

94 CTL(-) 0

95 CTL(+) 2.386

96 AMP C 2.399

97 CTL AMP 0

98 AMP VCC 5.08 CPU +5V

99 A VCC 5.08 CPU +5V

100 KEY0 4.84 TV keys

(11) TDA9183P(comb filter circuit)

Pin definition voltage remark

1 NC 0.87

2 GND 0

3 NC 1.56

4 GND 0

5 VDDD 4.85

6 VCCA 4.86

7 H.SYNC 3.70

8 GND 0

9 Fsc 0.65

10 NC 0

11 NC 0

12 CVBS input 1.8

13 GND 0

14 Y output 1.67

15 GND 0

16 C output 1.48

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2. curcuit explanation

(1)power curcuit In this set, the power curcuit uses STR-W6735, which is produced by Fairchild Company.

AC 120V voltage is input through the power line and goes through power filter L801 to the commutating bradge curcuit. After

commutated by D801\D802\D803D\D804, the DC voltage is got by C804. This voltage is equal to 1.4*AC input. If the input

voltage is 120V, then the voltage of C804 will be 168V. Through the primary coil of T801 and L802, the voltage connect to P1

of STR-W6735.

STR-W6735 has crystal oscillator in it. It can control the switching of the MOS curcuit in it automaticly. P4 is apply VCC voltage

for STR-W6735. The voltage is provide by R802 from AC voltage when the power line is first insert. R802 is named start-up

resistor. After starting up, the VCC voltage is provided by primary assistant coil of T801. The voltage is borned at P3 of T801

and goes through R805\D805 to P4 of STR-W6735. After D805, the DC voltage is got at C810. The voltage of P4 of

STR-W6735 is desired to between 9.7V and 27.7V. If the voltage is less than 9.7V, the STR-W6735 won’t start up. If the

voltage exceeds 27.7V, the overvoltage protection curcuit in STR-W6735 will operation and the working of STR-W6735 will be

stopped.

P5 of STR-W6735 is overload protection pin. Through the C807, the overload protection will operation.

P6 of STR-W6735 is feedback pin. STR-W6735 will adjust the working state according to the signal from the photocoupler.

P7 of STR-W6735 is overcurrent protection pin.

P4 of STR-W6735 provides VCC for inner control curcuit. After the control curcuit has started to work, the inner MOS transistor

will open and close according to the control curcuit. Then the DC voltage at C804 will go through the primary coil of T801 to

GND. The current will increase or fall linearly. Then there will be voltage at secondary side.

P10 of T801 is the voltage of +B . It is used for horizontal scan and +33V for tuner. The photocoupler samples from +B voltage

and the STR-W6735 will adjust its working according to the feedback of the sampling.

P12 of T801 is the voltage of 11V. This voltage is used for SW +9V. At the same time, it provides photocoupler with VCC.

P13 of T801 is the voltage of 6.5V. This voltage is used for SW +5V.

P11 of T801 is the common GND of P10\P12\P13.

P14 of T801 is the voltage of 6.5V. This voltage is used for DVD +5V.

P15 of T801 is the GND of P14.

P16 of T801 is the voltage of 16V. This voltage is used for VCR motor\DVD +12V\horizontaol LBT(T402).

P17 of T801 is the voltage of 13V. This voltage is used for sound amplifying curcuit.

P18 of T801 is the common GND of P16\P17.

(2) DVD function problem D812 on power board provides VCC of DVD +5V. AC voltage is supplied by transformer T801. R822 is a protection resister.

After D821, DC voltage is got at C816. I808 is a manostat for DVD +5V. It has a control pin to switch the +5V of DVD. The

control signal comes from the CPU on main board through the line of P806.

+5V is uses for DVD motor rotating and inner decoding curcuit.

If the R822 is a resistor of RF10-2W-0.27Ω-J-05-C, when the CRT is POWER OFF during the DVD loading, the DVD will not

work at the next POWER ON. When the set is POWER ON next time and changed to DVD mode, there will be no picture or

abnormal picture. One method is to take off the power line and then insert it back to the power socket again. If the method is

not accepted by user, a jumper to shorten R822 can solve the problem forever. Use a jumper and jointing it to the 2 sides of

R822. The products of first order have this problem. R822 is changed to a fuse resistor in the after production. So the after

productions have not the problem.

I807 is a manostat transisitor for DVD +12V. The voltage comes from D813 on the power board. +12V is used for DVD as



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sound amplifying VCC. If the +12V is not available at P805, the sound out of speakers will be very small in DVD mode.

(3) degaussing curcuit At P806 on the power board, there is a RLY.ON signal. After POWER ON by remote controller, there will be a high voltage on

the RLY.ON. Then the BE of Q806 will be turned on. The CE of Q806 will also be turned on. Then the relay will be turned on.

There will be current through the degaussing coil. Degaussing curcuit operates.

(3) Horizontal and Vertical scan curcuit. After CVBS signal has been received at P52 of LA76834, there is SYNC seperation curcuit integrated in I501. Horizontal pulse

signal is got at P30 and vertical pulse signal is got at P26. P29 is AFC filter for horizontal curcuit and P33 is flyback pulse

signal from FBT. P28 is VCC pin for horizontal pulse decoding curcuit and P53 is VCC pin for vertical pulse decoding curcuit.

P31 is horizontal GND and P49 is vertical GND. P20 is related to vertical size comparation. P27 is for vertical ramp ALC filter.

LA76834 sends out horizontal SYNC signal to I701 at P37 and vertical SYNC at P36. The CPU will send out RGB signal of

OSD to LA76834 when it receives the H SYNC and V SYNC. If there isn’t SYNC signal, the CPU will not send out RGB signal

of OSD.

Horizontal pulse signal is converted to power board through the line of P808. After R401, the signal is amplified by Q402.

M16V provides horizontal inspiriting VCC through Q804 to LBT(T402). After amplified by T402, the horizontal signal can drive

the horizontal transistor Q401. Q401 provides horizontal switching through FBT and +B voltage is used. Then linear current is

produced on the H-DY.

At the same time, saveral DC voltages appear at FBT.

(1) High voltage is about 27KV, used for CRT.

(2) VIDEO voltage is about 180V, used to amplify RGB signal on the CRT board.

(3) 24V voltage is used for vertical scan cuicuit.

(4) HEATER is AC voltage for heater of CRT.

(5) ABL signal is connected to main board through line of P808 after sampling resistor R414(1Kohm). LA76834

will adjust the output RGB range according to the ABL voltage at P11.

Vertical signal is converted to power board through the line of P808. After R301, the signal is send to P1 of LA78041(or

LA78040). 24V voltage is provided at P2 of LA78041 by FBT and out VCC can be got at P6 through a diode D303. Reference

voltage is got from 24V by R303 and R304. R316 and R 314 can adjust the vertical center. There are 3 methods as follows.

(1) Use only R316(1kohm or 2.2Kohm), the vertical center is highest.

(2) R316 or R314 not used. The vertical center is in the middle.

(3) Use only R314(1kohm or 2.2Kohm), the vertical center is lowest.

Vertical scan signal is output at P5 of LA78041 to V-DY.

(4) RGB amplifying curcuit. RGB VCC is provided to LA76834 through R511 at P16. Then RGB signal is output at P17/P18/19 and connected to CRT

board through the line of P902. RGB signal is amplified by transistor of Q901/Q902/Q903. 11V at P901 is used to provide E

DC voltage for Q901/Q902/Q903. 24V voltage is used to bring white screen on the CRT when power off. The capacitor C905 is

charged when power on and the voltage on the B of Q904 is high than E, so the CE of Q904 is not turned on. When the power

is turned off, the 24V voltage becomes to 0 and the voltage on C905 is still high. So the EB of Q904 is turned on and the EC is

turned on. High voltage goes to RGB electron gun, so white screen appears on the CRT.

Heater voltage is connected to CRT board by line of P901. Through R922, the voltage heats the CRT.

(5) Signal decoding process . (a) at TV mode, mono sound signal.



Tuner U101 outputs the IF signal and U102 is the SAWF.

After U102, the IF signal is send to P78 and P79 of LA76834.

LA76834 outputs the television signal at P56. After ceramic trap X4.5M, the CVBS signal of TV mode is formed.

The CVBS signal is send to P43(TV in) of MM1492.

MM1492 is controlled by M37762 through IIC bus. At TV mode, MM1492 obtains TV CVBS signal at P43 and outputs the

TV CVBS signal at P37(TV out).

The CVBS signal is send to P12 of TDA9183P.

After decoding, TDA9183P will send out the Y signal at P14 to P52 of LA76834 and C signal at P16 to P54 of LA76834.

(IF there are not TDA9183P, the CVBS signal is send to P52 of LA76834 directly. At the same time, the data in I703

should be changed. The comparison of with and without TDA9183P is as follows ) descr iption

posi tion

material

model

with TDA9183P

without TDA9183P

comb filte

I502

IC

TDA9183P

Yes

No

L551 inductance LGA0203-10µH-K-T52 Yes No L552 inductance LGA0203-10µH-K-T52 Yes No C551 capacitor chip 0603F103M500NT Yes No

VCC

C552 electrolytic capacitor

CD110X-16V-10µF-M-F05

Yes

No

R554

resistor chip

RS-0603-1/16W-47kΩ -J-E

Yes

No

H-SYNC R551 resistor RT13-1/6W-1KΩ-J-T52 Yes No

R552 resistor chip

RS-0603-1/16W-2.7KΩ -J-E

Yes

No

C553 capacitor chip 0603CG104J500NT Yes No J017 jumper φ0.58mm/7.5mm Yes No

fsc

R553 resistor chip

RS-0603-1/16W-10kΩ -J-E

Yes

No

C554

capacitor chip

0603F103M500NT

Yes

resistor chip (RS-0603-1/16W-0Ω-J-E)

No

add one jumper between P12 and P14 of I502.

C555

electrolytic capacitor

CD110X-50V-0.47µ F-M-F05

Yes,direction is the same as PCB board.

Yes，direction is opposite with the PCB board.

CVBS

C556 electrolytic capacitor

CD110X-50V-0.47µ F-M-F05

Yes

No

color carrier

C527

capacitor chip

39PF

30PF MAIN IC 18 11000000 10000000/1->0 : C.Ext service

mode data

MAIN IC

14

10000011

10000001/1->0 : Filter Sys.

LA76834 outputs H.SYNC signal at P37 and V.SYNC signal at P36. M37762 receives the SYNC signal and according to

the signal, it sends out RGB signal of OSD at P64\63\62 to P12\13\14 of LA76834.

LA76834 will mix the picture RGB and OSD RGB together and then sends out RGB signal at P17\18\19.

H.DRIVE signal is send out at P30 of LA76834.

V.DRIVE signal is send out at P26 of LA76834.

LA76834 sends out SIF(second sound IF) signal at P67. At the same time, it will get the SIF signal in itself.

LA76834 outputs the mono sound signal at P75.

The signal is connected to P42/43 of MM1492.

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4154

After controlled by IIC bus, MM1492 will selected the TV out signal at P42/43 and outputs it at P36/35.

Mono sound signal is send to P8/7 of TDA7449.

TDA7449 is controlled by IIC bus. The BASS\TRABLE\BALANCE data is send to it by M37762. When it sends out the

L/R signal at P5/4, the sound signal has been dealt with.

LA4635A receives the signal at P2/4.

LA4635A will outputs the amplified sound signal at P12/8 and it is send to speakers.

At the same time, TDA7449 will send out the sound signal to REAR audio out terminal. If we connect the audio out

terminal of 2 television of this model together, then every television gets the sound from the 2 sets. The sound will mix

together at TDA7449.

(b) at TV mode, stereo sound signal(use MTS). The picture decoding process is the same as (a).

The sound decoding process is different.

LA76834 outputs SIF signal at P67 and sends it to P57 of LA72670.

When LA72670 receives the signal, it will decoding the signal and judge it is mono or stereo or sap.

LA72670 will send out different voltage at P40. P40 of LA72670 is connected to P5 of M37762. Then M37762 will know it

is mono or stereo or sap signal.

Different types of sound signal will be processed differently. So, M37762 must know the information.

LA72670 outputs the L/R signal at P78/80 and the signal is received at P14/15(VCR in) of MM1492.

Because M37762 knows it is at the TV mode, and the sound signal is stereo, so M37762 controls MM1492 to select

signal from P14/15 for TV out.

MM1492 output stereo sound signal at P35/36(TV out).

(c) at TV mode, mono sound signal,VCR working at REC mode. CVBS signal of TV is send to the P43 of MM1492. P37 of MM1492 will output the CVBS signal to TDA9183P. At the same

time, P23 of MM1492 will output the CVBS signal to P32 of LA71207.

After inner decoding, LA71207 will output SP-L/SP-COM/SP-R signal at P65/P66/P67. The signal can be received by

VCR through plug P201.

After the REC order is send to the M37762, P20 will output high voltage, and Q204 will be turned off. Erase signal will be

got at T201 at plug P203. This head is named FE-HEAD. It can erase all the signal on the tape.

The width of the whole tape is 12.7mm. Position of signal on the tape is as follows.



4254

VCR will receive the SP-L/SP-COM/SP-R signal and record it on the tape through DRUM.

If the REC is SLP(EP) mode, the LA71207 will output the EP-L/EP-COM/EP-R signal at P72/73/74 to VCR through plug

P201. M37762 will control VCR through plug P204.

P204 is a plug for ACE-HEAD. The HEAD has AE-HEAD(audio erase head)/A-HEAD(recording or play back). It also has

the CTL HEAD to read or write the CTL+ and CTL- signal.

It is as follows.

P203 is FE-HEAD. At the REC mode, FE-HEAD first erase all the signal on the tape. Then the DRUM write the video

signal on the tape.

To ensure the normal audio signal has been erased totally, AE-HEAD is designed to erase normal audio signal again.

MM1492 gets mono sound signal of TV mode at P42/P44. It sends out the signal at P24/P26 to P7/P69 of LA72670.

Through inner curcuit, LA72670 will transfer the mono sound signal to LA71207 at P4.

LA71207 receives the signal at P10.

LA71207 will output audio signal, which are proper for VCR to record, at P11.

At the same time, M37762 outputs high voltage at P20, which are REC(H). Then audio signal is transferred through

Q209/Q208/T201. VCR can get the audio signal at P202, A.HEAD.

CTL signal is send out from P94/P95 of M37762. VCR gets the signal at P202.

(d) at TV mode,stereo sound signal,VCR working at REC mode.

The width is 1mm. It is used for normal audio signal.

The width is 10.7mm. It is used for video signal and HiFi sound signal.

The width is 1mm. It is used for CTL signal.

A B

The width is about 5um. It is used for HiFi audio signal.

A and B is video signal area. The width is about 54um in SP mode.

ACE-HEAD

CTL+ and CTL- HEAD

A-HEAD. To read the normal audio signal and write the signal to the tape.

AE-HEAD. To erase normal audio signal.



4355

The picture process is the same as (c).

SIF signal is send to P57 of LA72670.

LA72670 can adjust it is a mono signal or stereo signal or sap signal.

After inner decoding, LA72670 will outpus the L and R sound signal at P78 and 80.

MM1492 receives the signal at P14/P15(VCR in).

MM1492 will output the signal at P36/P35 to TDA7449 for TV to process and amplify.

At the same time, MM1492 will get the signal at P26/P24(VCR out), and output it to P7/P69 of LA72670.

After inner decoding, LA72670 will output the A-R/A-COM/A-L signal to plug P201.

The DRUM gets the signal and write it on the tape.

(e) VCR is on play back mode, mono sound signal(normal). VCR reads the video signal at DRUM and through the P201, the signal is send to LA71207.

If the tape is SP mode, the signal is received by LA71207 at P65/P66/P67. If the tape is SLP mode, it will be received at

P72/P73/P74.

LA71207 will send out ENVE signal at P14 to adjustment board for the VCR adjustment.

CVBS signal of tape will be send out at P26 of LA71207.

MM1492 receives the CVBS signal at P13(VCR in) and outputs it at P37(TV out).

Sound signal is read at ACE-HEAD of VCR and the signal is send to P6 of LA71207.

After inner decoding, sound signal is output at P10 and LA72670 receives it at P4.

Now P23 of LA72670 will be low voltage and send the informaiton to the P8 of MM37762.

After inner transferring, LA72670 will output the signal at P78/P80.

MM1492 receives the signal at P14/15.

(f) VCR is on play back mode, HiFi sound signal. VCR reads the signal through DRUM and the signal is transferred to P24/P26/P27 of LA72670.

LA72670 will decode the A-R/A-COM/A-L signal and output L/R sound signal at P78/P80.

After LA72670 receives the signal, it will outputs the high voltage at P23.

M37762 knows the information at P8 and sends out related orders.

MM1492 receives the signal at P14/P15(VCR in).

(g) Working on the DVD mode. DVD CVBS signal is send to P7 of MM1492.

DVD audio L/R signal is send to P8/P10 of MM1492.

(h) Working on VIDEO 1 mode. CVBS signal is send to P1 of MM1492.

Audio L/R signal is send to P2/P4 of MM1492.

(i) Working on VIDEO 2 mode. CVBS signal is send to P16 of MM1492.

Audio L/R signal is send to P17/P18 of MM1492.

(6) Passwords of parental control in TV and DVD. The initial password of parental control in TV is 0000. If users forget the password, 9443 can be used to regain the

password. This is a password which can be used forever.

The initial password of DVD is 1234. 1369 is a password which can be used forever.



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12. Adjustment A. Factory adjustment information

Method to enter the factory mode:press POWER to let the set go to STANDBY mode,then press DISP\MUTE\PICT\INPUT in turn. The set will be turned on and enter the factory mode. Press the UP and DOWN keys besides PLAY/ENTER to select the item, then press LEFT and RIGHT keys to enter the selected item. You can exit using MENU button. Factory mode means service mode.

B. Factory mode menu MODE FUNCTION REMARK 1. H/R Heat Run White pattern 2. SCRN Screen Bright. Horizontal line on the screen 3. S/T Sound Test Volume, Bass, Treble, Balance control 4. MAIN IC Main IC data Test Chroma IC data 5. AGC IF control RF AGC Delay point control 6. GEO Geometry Screen Center adjust 7. P/T Picture Test Bright, Contrast, Sharpness, Tint, Color adjust 8. WB White Balance White balance adjust 9. DP Digital Preset sub-bright control 10. FACT Factory Reset Set default data 11. PG PG Adjust PG Delay auto-adjust 12. PATH PATH Adjust Deck path adjust (center, max, min) Adjust methodes(TV) - Connect AC power cord of set. - Push buttons on remote controll in sequence as follows in stand-by mode DISPLAY -> MUTE -> PICT -> INPUT - Using / buttons, select the item you wish to adjust. - Using / buttons, enter the item you wish to adjust. - You can exit using MENU button. (1). H/R - Select H/R mode. - White pattern will be appeared on the screen. - Befor adjust factory data, heat-run should be excuted more than 30minitues. - Using MENU button, exit H/R mode. (2). SCRN - Select SCRN mode. - You can see the one horizontal line on the screen. Adjust the screen locating on FBT till the horizontal line may be disappeared. - Using MENU button, exit SCRN mode.



4554

(3). GEO - Receive cross-hatch pattern. - Select GEO mode. a. H-CENTER - Select H.CENTER, adjust that data to obtain proper horizontal centering b. V-CENTER - Select V.CENTER, adjust that data to obtain proper vertical centering c. V-SIZE - Select V.size, adjust that value to proper vertical size. - Using MENU button, exit GEO mode. (4). Focus - Receive mono-scope pattern. - Adjust the focus control volume locating on FBT to obtain clear pattern . (5). WB - Receive Black and White pattern. - Select WB mode. a. High Beam - Selcet R-DRIVE and B-DRIVE. - Adjust that value to obtain x=260, y=270 (Y=120) b. Low beam - Select R-BIAS,G-BIAS and B-BIAS. - Adjust that value to obtain x=260, y=270 (Y=15) c. Repeat a and b till no difference between low and high beam data. - Using MENU button, exit WB mode. (6). DP - Receive mono-scope pattern. - Select DP mode. - Adjust Sub-bright data to obtain proper raster. - Using MENU button, exit DP mode. (7). AGC - Receive color bar pattern that RF level is 60dBu. - Connet Jig at P101. - Select AGC mode. - Adjust that value to obtain 3.75V of Jig pin. - Using MENU button, exit AGC mode.

C. VCO adjustment If the picture is not steady at 80dB or 90dB, please adjust the VCO voltage. Method: let the TV receive the Philips color round signal; Use FLUCK multimeter to measure the DC voltage of the positive of C531; Adjust the L503 to let the voltage of the C531 become 3.6V.



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D. VCR adjustment Tools for adjustment: special tape SN-2; 1 cross screwdriver with out magnetism and 1 normal

screwdriver with out magnetism; 1 oscillograph and 2 probes; 1 special PCB board(named JIG) only for VCR adjustment. 1 AV line(RCA terminal)

Connect the JIG to P208 on the main board. Connect CH1 of oscillograph to the S/W jumper on the JIG, connect CH2 on the

ENVE jumper. Put SN-2 tape into the VCR and the VCR will play automaticly. Let VR1(500K) on the JIG in the middle. (1) adjust entrance (P2) and exit (P3).

P2 is signed 4(GUIDE ROLLER) in the upper chart. P2 is signed 8(GUIDE ROLLER) in the upper chart. Adjust the P2 and P3 until the signal on CH2 of the oscillograph becomes horizontal. Turn the VR1(500K) clockwise. If the signal on CH2 is not horizontal, adjust P2 and P3 again. Turn the VR1(500K) anticlockwise. If the signal on CH2 is not horizontal, adjust P2 and P3 again. When adjustment is OK, put the VR1(500K) in the middle.

(2) adjust X-position to let the signal on CH2 biggest.

X-position



4754

(3) adjust VCR sound output.

Connect the RCA line to the rear audio output terminal. Connect the CH2 on the oscillograph to the RCA line.

Adjust Azimuth to let the signal on the CH2 biggest.

(4) adjust SERVO/SYSCON to 6.5H. Connect the CH2 to the RCA line and connect the RCA line to the rear video out terminal. 1H=63.3us. The signal on CH2 should be as follows.

Press REC during the SN-2 is being played. The CPU of TV will adjust the time automaticly. The time showed on the oscillograph should between 6H(379.8US) and 7H（443.1US）. If not, press REC again. If the time is not proper, there will be a horizontal line at the bottom of screen during the VCR is

playing back.

All the adjustment of VCR has been finished, take out the SN-2 tape.

Azimuth


Documents

SERVICE MANUAL - rtellason.comrtellason.com/manuals/TV-8888-69.pdf · COLOUR TELEVISION SERVICE MANUAL ... In the Schematic Diagram and Replacement Parts List. It is essential that