DAEWOO DTQ-26S1FC, DTQ-26S1FS, DTQ-26S1FSP, DTQ-29S1FCN, DTQ-29S1FSN Service Manual

...

Service Manual

Color Television

CN-200I/A

CHASSIS

NTSC-M SYSTEM

MODEL

DTQ-26S1FC/FS/FSP(CN-200I)

DTQ-29S1FCN/FSN/FSP(CN-200I) DTQ-26S1HC/HS/HSP(CN-200A) DTQ-29S1HC/HS/HSP(CN-200A)

DAEWOO ELECTRONICS CO., LTD. OVERSEAS SERVICE DEPT.

FEATURES

FS (Frequency Synthesizer) Tuning System CATV Ready Monitor Look Design A/V IN. (Stereo) Stereo/Mono Function

ELECTRICAL SPECIFICATIONS

POWER INPUT

FC SERIES AC 120V 60Hz FS SERIES AC 85V ~ AC 150V 60Hz FSP SERIES AC 220V 50Hz/60Hz

POWER RATING

26” MODELS 100W 29” MODELS 105W

INTERMEDIATE FREQUENCIES

PICTURE IF CARRIER FREQUENCY 45.75MHz SOUND IF CARRIER FREQUENCY 41.25MHz

COLOR SUB CARRIER FREQUENCY 42.17MHz AUDIO OUTPUT RATING 1.2W 2 SPEAKER 2W 8 ohm 2 ANTENNA INPUT IMPEDANCE VHF/UHF 75 ohm UNBALANCED TUNING RANGES

VHF 2 THRU 13

UHF 14 THRU 69

CATV 1 THRU 125

CONTENTS

Safety Precautions 3 Control View 5 Important Service Notes 7 Block Diagram 8 General Adjustments 10 Trouble Shooting Charts 12 Description of Semiconductors 20 Printed Boards 21 Exploded View 23 Schematic Diagram 25 Parts List 27 Option List 36

CONTROL VIEW

F-CONNECTOR

300 OHM-75 OHM COUPLING TRANSFORMER

VHF

75Ω

FROM 75 OHM VHF ANTENNA WITH CABLE OR CABLE TV SYSTEM

1. Overview of Your Equipment

Your TV comes with a remote control. The section below summarizes the buttons,controls, and terminals that you will use with your TV.

2. Your TV' s Front Panel

1. POWER

Use this buttom to turn your TV on or off.

2. CH

Use these buttom to change channels on your TV, or to select items in the menu system.

3. VOL

Use these buttom to change your TV s volume, to activate selections in the menu system, or to change audio and video settings.

4. MENU

Use this buttom to turn the TV s menu system on and off.

5. Remote control receiver

This receiver receives a signal from your remote control. Do not block it.

3. Your TV' s Back Panel

1. Antenna terminal

Use this terminal to attach an antenna or cable system to your TV.

2. VIDEO IN

This terminal allows the TV to receive a video signal from another components, such as a VCR.

3. AUDIO R/MONO IN

This terminal allows the TV to receive an audio R/MONO signal from another components, such as

a VCR.

4. AUDIO L IN

This terminal allows the TV to receive an audio L signal from another components, such as a VCR.

BLOCK DIAGRAM (CN-200I)

BLOCK DIAGRAM (CN-200A)

GENERAL ADJUSTMENTS

1. GENERAL

In the majority of cases, all color televisions will need only slight touch-up adjustment upon installation. Check the basic characteristics such as height, focus and sub- basic characteristics such as height, focus and sub- bright. Observe the picture for good black and white details without objectionable color shading.

2. VERTICAL HEIGHT ADJUSTMENT

1) Tune in an active channel.

2) Adjust brightness and contrast controls for a good picture.

3) Adjust vertical height control (R305) for approximately one

half inch over scan at top and bottom of picture screen.

4) Vertical centering adjustment R310

Horizontal centering adjustment R516.

3. FOCUS ADJUSTMENT

1) Tune in an active channel.

2) Adjust brightness, sharpness and contrast controls for a

good picture.

3) Adjust focus control (part of T402) for sharp scanning lines

and/or sharp picture.

4. RF AGC ADJUSTMENT

1) Tune in an active channel.

2) Using the attenuator, apply the signal of 60dBm to the

antenna input terminal.

3) Turn RF AGC control (R113) full clockwise until snow

or/and noise appears in the picture, then slowly turn control counter clockwise until snow or/and noise disappears.

5. HIGH VOLTAGE CHECK

High voltage is not adjustable but must be checked to verify that the receiver is operating within safe and efficient design limitations as specified:

1) Operate Receiver for at least 15 minutes at 120V AC line.

2) Set brightness sharpness, contrast and color control to

minumum position (Zero beam).

3) Connect accurate high voltage meter to CRT anode. The

reading should be 26kv~28kv

clockwise.)

4) Rotate the RED, GREEN and BLUE BIAS controls (R917, R918, R919) counterclock wise from the maximum, set them to the position where notches in the knobs become parallel to the surface of P.C. Board.

5) Set the GREEN and BLUE DRIVE controls (R920, R921) to the mid position.

6) Turn the service switch SW901 (Service Position) on the CRT board.

7) Rotate the SCREEN control (on T402) gradually clockwise until the second horizontl line following the first line appears slightly on the screen. Then turn fully counterclockwise the two BIAS controls corresponding to the colors of the first and the second horizontal lines to eliminated the lines.

8) Set the SCREEN control to the position where the third horizontal line lights slightly on the screen.

9) Adjust the two BIAS control set to the minimum in item 7) above to obtain the slightly lighted horizontal line in the same levels of three (red, green, blue) colors. (The line should be white if the BIAS controls are adjusted properly.)

10) Turn the service switch SW901 again (Normal position on the CRT board.)

11) Press PICTURE-SEL, P-UP and set the brightness and contrast controls to the maximum.

12) Adjust the BLUE and GREEN DRIVE control to obtain proper white-blanced picture in high light areas.

13) Using P-SEL, P-DN key, set the brightness and contrast controls to obtain dark gray raster. Then check the white balance in low brightness. Of the white balance is not proper, retouch the BIAS controls and DRIVE controls to obtain a good white balance in both low and high light areas.

8. MAIN B+(103V) ADJUSTMENT

1) Tune in an active channel

2) Check TP10 (DC 103V Line) using D.V.M

3) Adjust voltage control (R809) for main B+(DC 103V)

If a correct reading cannot be obtained, check circuity for malfunctioning components.

6. X-RADIATION PROTECTION CIRCUIT TEST

When service has been performed on the horizontal deflection system, high voltage system or B+system, the XRADIATION protection circuit must be tested for proper operation as follows:

1) Operate receiver for at least 15 minutes at 120V AC line.

2) Adjust all customer controls for normal picture and sound.

3) Short R414(X-RAY Short test), and remove short clip.

4) If the operation of horizontal osc. does not stop in step The circuit must be repaired, before the set is returned to the customer.

7. CRT GRAY SCALE ADJUSTMENT

1) Tune in an active channel.

2) Set the COLOR control to minimum.

3) Turn the SCREEN control (on T402 fully counter-

9. SUB-BRIGHTNESS ADJUSTMENT

1) Tune in a color program.

2) Set the CONTRAST control to maximum and the BRIGHTNESS control to maximum and the SHARPNESS control to the center position.

3) Set the COLOR and TINT controls to center.

4) Set the SUB-BRIGHT control R522 to center and leave the receiver on five minutes in this state.

5) Watching the picture carefully, adjust the SUB-

BRIGHT control in the position where the picture does not show evidence of blooming in high brightness area and not appear too dark in low bright area.

6) Check for BRIGHTNESS controls at both extremes.

7) If the picture does not appear dark with the

CONTRAST and BRIGHTNESS control turned to minimum, or not appear bright with the controls turned to

maximum, adjust the SUB-BRIGHT control again for an acceptable picture.

10. PICTURE IF/AFT ADJUSTMENTS

NOTE

: THIS RECEIVER IS TRANSISTORIZED AND SPECIAL CARE MUST BE TAKEN WHEN SERVICING. READ

THE FOLLOWING (NOTES BEFORE ATTEMPTING ALIGNMENT)

Alignment requires an exacting procedure and should be undertaken only when necessary. Isolation transformer must be used to prevent shock hazard. The test equipment specified or its equivalent is required to perform the alignment properly. Use of equipment which does not meet these requirements may result in improper alignment. Accurate equipment is essential to obtain proper alignment of this receiver. Use of excessive signal from a sweep generator can cause overloading of receiver circuit Overloading should be avoided to obtain a true response curve. Insertion of markers from the marker generator should not cause distortion of the response curve. The AC Power line voltage should be kept 120 volts while alignment is being performed. Do not attempt to disconnect any components while the receiver is in operation. Make sure the power cord is disconnected before replacing any parts in the receiver.

TEST EQUIPMENT Digital voltmeter National Model VP-2600A or equivalent Oscilloscope Direct/Low-capacity probe

Tektronix Model 2215A or equivalent. Tektronix Model P6120 or equivalent

(Accessory of oscilloscope) Color-Bar/Dot/Crosshatch generator PIF sweep marker generator Power supply Isolation transformer

Tektronix Model 146 or equivalent.

Nihon Tsushinki Model 4723 or equivalent

Academy Model 150A or equivalent

Voltage adjustable type having capacity of

at least 150 watts

BLOCK DIAGRAM

OUT

OSCILLOSCOPE

45.75MHz

Fig. 6 PIF Response

45.75MHz

Fig. 7 AFT Response Curve

B+

BIAS POWER SUPPLY A (12V)

AGC

BIAS POWER SUPPLY B (4-5V)

1) Disconnect the

MAIN BOARD

TP3

TP5

PIF SWEEP/MARKER GEN.

Fig. 5 Picture IF Sweep Alignment

TP7

TP6

DETIN

TUNER IF output from TP6 and connect equipment as shown above.

2) Set the sweep/marker generator for 30 Vrms.

3) Observe 1 Vp-p on scope by adjusting power supply B (4~5V).

4) Adjust PIF coil L505 for according beat signal with 45.75 MHz marker on scope (See Fig. 6).

5) Connect the

DET IN to TP7.

6) Adjust AFT coil L504 for center display at 45.75 MHz on scope (See Fig. 7).

7) After completing the above steps, disconnect equipment and adjust the AGC delay circuit as explained in the General

Adjustments section of this manual.

TROUBLE SHOOTING CHARTS

NO POWER

DOES QC701(POWER ON/OFF TR)

OPERATE?

CHECK TP10 (MAIN B+ LINE)

R816 15K 2WATT

103V

IF #26 NORMAL & NO OUTPUT AT #23 THEN CHANGE I501

YES

CHECK

#30 (7.5V

)

I501

Q402 H. OUTPUT

12V 12V

D406

GO TO

T402 F.B.T

DOES SHUT DOWN CIRCUIT OPERATE?

CHECK Q402 COLLECTOR

SHOULD BE

4.3V-5.2V

Q802 REGULATOR

CHECK F801 125V 5A

CHECK LEAD SOLDERING

QC706 RESET

R808

T801

L801 LINE FILTER

CHECK 12V LINE

NORMAL: 5V RESET: 0V

I701 LC864616A

QC701 POWER CONTROL

D403

OPEN LOAD THEN CHECK #42 ON STATE 4 ~5V

103V(B+)

CHECK ALL THE POINTS THEN CHANGE I701

PWR CONTROL KEY

KEY OPERATE? CHECK DIODE D701 & SWITCH KEY BOARD

NO PICTURE

CHECK CONTROL (NORMAL) VOLTAGES #39: 5.0V #31: 3.9V

CHECK THE WAVE FORM OF I501 #44 (2Vp-p)

QC201

CONTRAST

BRIGHT

D505 ABL

COMPOSITE VIDEO INPUT

R522 SUB-BRIGHT

C506

CHECK 9V LINES #11,14

I501 LA 7674

11 14

CHECK ABL Ib = 1.2mA

GO TO

Y-OUT

H. BLANKING

T402 FBT

ABL H.T

QC501 VIDEO DRIVE

CHECK 210V KINE

D404

R413

R412

ENA

I701 LC864616A

CHECK CSB503E

DATA

1110

CLK

U101 TUNER

Z101 SAW FILTER

CHECK IF AGC VTG. 5V

TP2

AGC

8 9

(33V)

ADJUST RF-AGC R113

I501 LA7674

DETECTOR OUTPUT

44 14112

CHECK

9V LINE

#11, 14

CHECK HEATER

6.3Vrms

TO QC201

NO SOUND(CN-200I)

CHECK FOR SIGNAL AT I501 #1

CHECK MONO 100% MOD

-> 0.424 Vp-p

CHECK

EXT SOUND

SIGNAL OFF:L

(B+)

#2 9V

#12 #13

#1 9V

(B+)

#2(0~5V)

I602

I601

(MUTE)

#4 #6

#19 #18 #17

CHECK 1Vp-p

MUTE ON: 5V OFF: 0V

GO TO

CHECK SOUND INPUT

CHECK 9V

Z201

CHECK SOUNDIF INPUT

#11 #14

#44

#48

#8(0~5V)

I604/I603

I501 LA7674

#6 #5

CHECK 12VDC

CHECK SOUND OUTPUT

COMPOSITE SIGNAL

CHECK FM DET CIRCUIT

I601 #1

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