Daewoo Training Manual 2

Jun . 2002

DAEWOO ELECTRONICS CO., LTD.http : //svc.dwe.co.kr

PRODUCT : COLOR - TV

Training Manual

Table of contents

Chapter 1. TV Standards

1. Introduction---------------------------------------------------- 2

2. Trend of Trouble--------------------------------------------- 4

3. How to Progress The Diagnosis of Trouble---------- 5

4. Understanding of Trouble Symptom-------------------- 5

5. Diagnosis of Trouble---------------------------------------- 7

6. Notes------------------------------------------------------------ 9

7. Color Television Circuit System------------------------- 10

Chapter 2. Trouble Shooting Charts

1. CN-001N CHASSIS----------------------------------------- 11

2. CP-185 CHASSIS------------------------------------------- 17

3. CP-385 CHASSIS------------------------------------------- 22

4. CP-785 CHASSIS------------------------------------------- 27

1

Chapter 1. TV Standards

1. Introduction

The first, color television system to be used for a public broadcast service was the

CBS(Columbia Broadcasting System) field sequential system which was adopted in

the United States in 1951.

The CBS system was subsequently replaced by the NTSC(National Television

System Committee) system which transmits all three primary signals simultaneously.

The NTSC system has been used for public broadcasting on the USA since

December 1953.

The NTSC system, which operates on a 60HZ field and 525 Scanning lines, is designed

to be compatible with the monochrome TV system in the US. The width of the video zone

is 4.5MHz and the width of the channels is 6MHz.

This system has been adopted in the USA, KOREA,CANADA,JAPAN and other countries,

and particularly where the utility electricity mains supply frequency is 60Hz.

The PAL system was proposed by W.Bruch of Germany, PAL is stand for "Phase

Alternation by Line". This system was adopted by many European Countries and

public broadcasting began in 1967 in Germany. This system is almost the same as

the NTSC system for the color TV signals, but differs in the fact that the signal are

inversed by 180 at every horizontal scanning line, therefore using a 1H delay line in the

color receiver, suing a 625 line, 50 field.

The SECAM system broadcast service began in FRANCE in 1967 which was officially

adopted by France, USSR and other countries.

The SECAM is stand for "Sequential couleurs A Memoire" This system operates on a 625

lines, 50 fields, was based on the two distinguishing features of the system,

the use of segmental color signals a memory device, the memory device took the from

of a 1H delay line in the receiver.

This system has disadvantages in the parts of phase divergence and cross talk(leakage

of signals) because of the way that the color signals,divided into two,are simultaneously

transmitted.

2

FORMAT

FEATURE

525 625 625

15.734 15.625 15.625

59.94 50 50

29.97 25 25

2 : 1 2 : 1 2 : 1

4 : 3 4 : 3 4 : 3

AM - AM - AM +

FM±25 FM±50 AM 60%

4.2 5 6

4.5 5.5 6.5

6 7 8

3.579545 4.433618 R=4.40625,B=4.25

USA, GERMANY, FRANCE,

JAPAN, W-EUROPE E-EUROPE,

KOREA CHINA, CIS

FCC CCIR CCIR

VIDEO BAND (MHZ)

STANDARD SPEC

SOUND CARRIER (MHZ)

CHANNEL BAND (MHZ)

COLOR CARRIER (MHZ)

COUNTRY

INTERLACED SCANING

ASPECT RATIO

VIDEO MODULATION

SOUND MODULATION (KHZ)

SCAN LINES (H)

H-FREQ (KHZ)

V-FREQ (HZ)

PICTURE PER SEC

TV SYSTEMS STANDARD

NTSC PAL SECAM

3

2. TREND OF TROUBLE

TV receiver is composed of a great many components and the number of which

can be different in accordance with each model. But even that only one of its

composed components is trouble, the TV receiver doesn't operate normally.

The lower the ratio of generating the trouble and the less the number of composed

components are used, the higher the reliability of the receiver is assured.

When using a receiver mode of vacuum tube the trend of trouble increases as time

goes by, but as transistor and IC make an appearance and the used components

decrease considerably be means of employing the integrated circuits,considerable

decreasing of trouble is resulted.

Recently,trouble-shooting which is required of exchanging the whole PCB as well

as the troubled components serves as the assurance of reliability and the satisfaction

of customer.

- BATH TUBE CURVE (TREND of TROUBLE) -

4

3. HOW TO PROGRESS THE DIAGNOSIS OF TROUBLE

It is not easy to repair the TV sets with prompt and accurate by clarifying

the reason of trouble out of a great many components unless the composition of

each circuit and the flow of signal should be understood systematically.

The diagnosis of trouble in TV receiver usually can be localized a major

section by observing the symptom of it. That is, an efficient order of

diagnosis, first divide the total into the two blocks and find the block in which the

trouble occurs, and again divide the block into two more in detail, by this repeat

procedures, localize to narrow section, and detect the component caused to be trouble.

The order of diagnosis is progressed as follows.

1) Observe the symptom of trouble

2) Presume the troubled circuit from the symptoms

3) Localize the trouble to a narrow section(circuit break down)

4) Find the troubled component and check

5) Replace it by a good part of the same specification.

6) Make sure the set is operated normally.

4. UNDERSTANDING OF TROUBLE SYMPTOM

It's said that the troubleshooting is started from the feeling of the strange of

picture of sound,ended to check the normal operation. Therefore understanding of

symptom is the source of shooting and short way of able to repair with efficient

and sure and also it is very important to obtain the further more information from it.

If you wish to presume the circuit of troubled, you should know the flow of signals

and each operation ,and understand the situations for the troubled circuit corresponding

to its symptom.

While as above mentioned, the diagnosis of trouble in TV receiver can be localized

to narrow section by observing the raster and picture and by listening to sound.

TV receivers exhibit the specific signs for some definite troubles, For instance no high

voltage with normal sound means no brightness on the screen.

5

Localizing the trouble to one stage and a specific component generally should be

required of test equipment such as the multimeter, oscilloscope, and pattern

generator etc.. Just with a simple ohm-meter, test of opened-resistor and

short-capacitor is possible once the trouble has been narrowed down a suspected

component. It's summarized the relation of the symptom of trouble and its circuit.

[ TABLE 1] RELATION OF SYMPTOM AND CIRCUIT

SYMPTOM OF TROUBLE RELATED CIRCUIT

NO RASTER AND NO SOUND POWER, H-DEFLECTION, u-COM,FBT

NO RASTER AND NORMAL SOUND HV,CRT,FBT

NO PICTURE AND NO SOUND LOW B+ LINE,TUNER,IF AMP,AGC,u-COM

NO PICTURE AND NORMAL SOUND VIDEO DETECTOR,VIDEO AMP,VIDEO SWITCHING

CHROMA BPF,AGC,BURST AMP,CHROMA,OSCILLATOR

COLOR KILLER,CHROMA SWITCHING,COLOR CONTROL

INCORRECT COLOR COLOR DEMODULATOR,COLOR MATRIX,CRT DRIVE

SINGLE HORIZONTAL LINE V-DEFLECTION

CONVERGENCE DY AND PC MAGNET,CRT

NO HOLD SYNC. SYNC SEPARATOR,AFC,H-OSCILLATOR,AGC,APC

SOUND BPF,SOUND DEMODULATOR AND AMP

VOLUME CONTROL,MUTE,SPEAKER

SINGLE VERTICAL LINE H-DEFLECTION

NO COLOR

NO SOUND

6

5. DIAGNOSIS OF TROUBLE

Generally because the TV circuits are composed of so many components it's

not easy to cover the wide range of total parts. Therefore you should presume the

location of trouble by dividing the circuit into the narrow section.

When trouble-shooting is carried out, the multimeter and oscilloscope are mainly

used and by checking the voltage and waveform of each terminal the troubled

component can be detected.

Above all it's very important to accumulate the experience of repair through trial

and error understanding the flow path of signals.

5.1 DIAGNOSIS OF PASSIVE COMPONENTS (RLC)

Opening, short of R,L and C or reduction of capacitance value can be checked

with a simple tester, and only opening test can be also achieved by connecting a

good part with parallel. Poor insulation and short test should be done with a

tester after turning the power off.

While, It is required of alternative testing, which measures the value alternativery by

changing the probe direction of tester, because low value may be read due to the influence

of short components. In this case the larger one is selected out of measured values.

In case that it is difficult to determine whether the part is poor or not due to the effect

of other parts, check it after opening the lead.

7

5.2 DIAGNOSIS OF TRANSISTOR CIRCUIT

In the transistor amplifier circuit, forward bias current, forward bias current flow across base and

emitter, its forward voltage is, regardless of the type of transistor, about 0.7V in silicon TR and 0.2V

in germanium TR.

After measuring VB,VE,VC AND VBE, consider it as a normal if the following conditions are satisfied

1) VBE is about 0.6V(or 0.2V), that is, forward biased.

2) VB, VE and VC are within ±20% of the value specified in circuit.

Determination of trouble is also done by checking the resistance across the base and emiter,

base and collector, emitter and collector.

That is, after measuring the forward and reverse resistance, if its difference is large it is a normal.

If its difference is small, on the contrary, if its difference is large it is a possible to check it by

the short test with a digital multimeter.

5.3 DIAGNOSIS OF IC CIRCUIT

In case the troubled circuit contains IC the reason of trouble can be IC itself or surrounding

parts. For diagnosis, first compare the voltage of each terminal with the specification, if it

appears to be the difference of ±20% it can becaused to be the reason of trouble.

While as the reason of trouble, there is a case that the supply voltage is wrong and each

terminal voltage of IC is wrong regardless of the normal supply voltage.

In this case try to exchange IC after checking the surrounding components.

As above mentioned troubleshooting is completed by only charging the poor component

for a good one, but in accordance with the circuit there can be a case which is required of

readjustment of bias or frequency etc..

In a way of preventing the recurrence of trouble, knowledge of troubled reason is important.

8

6. NOTES

Remarkable items are described in below on troubleshooting, especially special

attention should be paid to dealing with TR and IC as they are very weak to heat

such as overcurrent and static electricity.

1) Turn the power off when soldering the component.

2) Don't short the circuit during operation as TR or IC can be destroyed.

3) Solder certainly the parts dealing with large power.

4) Use the specified components when changing.

5) Return the wire originally after troubleshooting.

6) Use the soldering iron grounded at the shim of it.

7) Have on the earth ring when dealing with IC or TR.

8) Don't touch the back side of PCB with a bare hand, especially take care for

the part of high voltage.

9

10

7. COLOR TELEVISION CIRCUIT SYSTEM.

A SCHEMATIC DIAGRAM OF A COLOR TELEVISION SIGNAL TRANSMISSION SYSTEM. THERE ARE FOUR BLOCKS IN TV SYSTEM.

1) VIDEO / SOUND SIGNAL PROCESSING PART

2) DEFLECTION (HORIZONTAL / VERTICAL) PART

3) COLOR SIGNAL PROCESSING PART

4) POWER SUPPLY PART

TUNER

AFT SOUND

DETECT

SOUND

IF AMP.

SOUND

FM DETECT

SOUND

AMP.

VIDEO

IF

VIDEO

DETE

VIDEO

AMP

COLOR

OUTPUT

AGCBAND

AMP

COLOR

DEMOD.

ACC

COLOR

KILLER

V-DEL

AMPV-OUT

H-DEL

AMPH-OUT

BURST

AMP

COLOR

SYNC

SYNC

H-V

POWER

SPK

CRT

DY COIL

11

CN-001N Trouble Shooting Charts

1. NO POWER

12

Trouble Shooting Charts

2. NO PICTURE

Check the waveform of I101 #46NG : GO to the figure c

OK : Go the figure d

1701 MICOM

CN-001N

13


3. NO SOUND

Check audio output signal of I101 #1NG : Go to the figure e

OK : Go to the figure f g

1701 MICOM

CN-001N

14


4. CH DON’T STOP

Check the input signal conditionsNG : Loss of signal or weak signal

OK : Go to the figure h

CN-001N

15


5. NO COLOR

6. NO VERTICAL DEFLECTION

CN-001N

16


7. NO ON-SCREEN DISPLAY

8. REMOTE CONTROL DOES NOT OPERATE

CN-001N

CHECK MAIN B+(+123V/+110V) LINE

CHECK VOLTAGE AT(+) OF C805 (400V 120uF)

310Vdc AT 220V

CHECK/REPLACE F801FUSE(F4AH 250V)

CHECK/REPLACEI801(STR-F6653)& PERIPHERAL COMPONENT

CHECK HORIZONTALDRIVE PULSE AT PIN 33

OF I501(TDA9361)[REFER TO WAVE FORM 9]

CHECK/REPLACED801,D802,D803,D804

(1S1888)R819 (7W 3.3OHM)

CHECKVcc(+8V DC) ATPIN 14 OF I501

CHECK/REPLACEQ402(2SD1207)T401(TD-10A2)Q401(2SD2499)

CHECK POWER SWITCHINGVOLTAGE AT PIN 63 OF I501

*POWER ON : HIGH*STAND-BY : LOW

CHECK/REPLACE

I823 (3.3V Reg)

CHECKSDA(PIN2)

&SCL(PIN3)

CHECK VOLTAGE(+3.3V DC)AT PIN 61 & 56 OF I501 CHECK/REPLACE

D840 (1N4148)D830 (BYV95C)

CHECK/REPLACE

T402 F.B.T& CRT

CHECK SDA(PIN 3)& SCL(PIN 2)

WAVEFORM OF I501

CHECK/REPLACEX502(12MHz)

CHECK/REPLACEI501

OK

CHECK HEATER VOLTAGE,VIDEO B+(185V) LINE,

11V & 45V LINE

ABNORMAL NORMAL

ABNORMALNORMAL

CHECK/REPLACEI804(LTV-817C)

ABNORMAL NORMAL

ABNORMAL NORMAL

NORMAL ABNORMAL

NORMAL ABNORMAL

ABNORMAL

NORMAL

ABNORMAL

OK

17

Trouble Shooting Charts (CP-185)

1. NO RASTER

ABNORMAL

NORMAL

(TDA9361)

18

CP-185 Trouble Shooting Charts

2. NO PICTURE (RASTER OF)

CHECK VIDEO SIGNAL AT PIN 38 OF 1501(TDA9361)

[REFER TO WAVEFORM 2 ]

CHECK VIDEO SIGNAL AT PIN 23 & PIN 24 OF I501

CHECK / REPLACEI 501

CHECK WAVEFORM AT PIN 40 OF I501

CHECK VIDEO SIGNAL AT PIN IF OF TUNER [REFER

TO WAVEFORM 1 ]

CHECK WAVE FORM AT PIN 50, 51, 52, 53 OF I501

CHECK VOLTAGE AT PIN OF TUNER

CHECK / REPLACE TUNER

CHECK VIDEO SIGNAL AT CATHOD OF CRT

CHECK / REPLACE CRT

OK

CHECK / REPLACEQ502, Q503

CHECK / REPLACE SAW FILTER

(SF01)

CHECK / REPLACE D408, I820

CHECK / REPLACE I901 (TDA6107Q)

ABNORMAL

ABNORMAL

ABNORMAL

ABNORMAL

ABNORMAL

NORMAL

NORMAL

NORMAL

NORMAL

ABNORMAL NORMAL

NORMAL

NORMAL

OK

19


3. NO VERTICAL SCANNING ( ONE HORIZONTAL LINE ON SCREEN)

CHECK / REPLACEP401 & DY

CHECK SIGNAL ATPIN1 & PIN2 OF I301 [REFER

TO WAVEFORM 10 11 ]

CHECK VERTICAL Vcc 11V ATPIN3 & 45V AT PIN6 OF I301(TDA 8357J)

CHECK / REPLACED407(IN4936GP)D408(IN4936GP)

CHECK SIGNALAT PIN7 OF I301

CHECK / REPLACER305, D350

D313

CHECK OUTPUTWAVEFORM AT PIN21, PIN22

OF I501

CHECK / REPLACE I301

CHECK / REPLACECRT

CHECK / REPLACEI501

OK

ABNORMAL

ABNORMAL

NORMAL ABNORMALABNORMAL

NORMAL

NORMAL

NORMAL

20


4. NO SOUND ( PICTURE OK )

CHECK AUDIO SIGNALAT PIN 44 OF I501

CHECK MUTE VOLTAGEAT PIN 62 OF I501

(*MUTE : HIGH)

CHECK S/F SIGNALAT PIN 23 & 24 OF I501


CHECK / REPLACESF01

CHECK SIGNAL WAVEFORMAT PIN1,PIN8 & PIN16 OF I101(TDA9830)CHECK VOLTAGE 8V AT PIN14 OF I101

CHECK / REPLACE I601(TDA7055)

[ I601(TDA1519B) ]

CHECK VOLTAGE Vcc(13.5Vdc) AT PIN1

(TDA 7267A)

CHECK AUDIO OUTPUT SIGNAL AT PIN2 OF I601

(TDA 7267A)

CHECK POWERPART CIRCUIT

CHECK / REPLACED813, C821

CHECK MUTE VLATAGEAT PIN12 OF I101

(MUTE : HIGH)

CHECK / REPLACEI101 (TDA9830)SAW FILTER

OK

ABNORMAL

NORMAL

NORMAL

ABNORMAL

NORMAL

NORMAL

ABNORMAL

ABNORMAL

NORMAL

NORMAL

ABNORMAL

NG

OK

NORMAL

ABNORMAL

( SECAM L/L’)

21


5. REMOTE CONTROL UNIT TROUBLE ( LOCAL CONTROL OK )

CHECK / REPLACEQ1 / LED1

(TRANSMITTER BOARD)

CHECK PULSE AT COLLECTOROF Q1 ( TRANSMITTER BOARD)

CHECK IC1(DHR-0015)

CHECK / REPLACEX1, C1

CHECK PULSEAT PIN36 OF I701

CHECK / REPLACEI704 (TFMU5380)

CHECK / REPLACEI701 & PERI, COMP

OK

ABNORMAL

NG

NG ABNORMAL NORMAL

OK

OK

CHECK MAIN B+(+123V/+110V) LINE


310Vdc AT 220V






(1S1888)R819 (10W 3.3OHM)





CHECK/REPLACE

I823 (3.3V Reg)

CHECKSDA(PIN 2)

&SCL(PIN 3)


D840 (1N4148)D830 (BYV95C)

CHECK/REPLACE

T402 F.B.T& CRT


WAVEFORM OF I501


CHECK/REPLACEI501

OK


11V & 45V LINE

ABNORMAL NORMAL

ABNORMALNORMAL


ABNORMAL NORMAL

ABNORMAL NORMAL

NORMAL ABNORMAL

NORMAL ABNORMAL

ABNORMAL

NORMAL

ABNORMAL

OK

22


1. N O RAST E R

ABNORMAL

NORMAL

(TDA 9367)

23









TO WAVEFORM 1 ]





CHECK / REPLACE CRT

OK



(SF01)



ABNORMAL

ABNORMAL

ABNORMAL

ABNORMAL

ABNORMAL

NORMAL

NORMAL

NORMAL

NORMAL

ABNORMAL NORMAL

NORMAL

NORMAL

OK

24




CHECK SIGNAL ATPIN 1 & PIN 2 OF I301 [REFER

TO WAVEFORM 10 11 ]

CHECK VERTICAL Vcc 11V ATPIN 3 & 45V AT PIN 6 OF I301(TDA8357J)


CHECK SIGNALAT PIN 7 OF I301


D313

CHECK OUTPUTWAVEFORM AT PIN 21, PIN 22

OF I501


CHECK / REPLACECRT

CHECK / REPLACEI501

OK

ABNORMAL

ABNORMAL


NORMAL

NORMAL

NORMAL

25



CHECK AUDIO OUTPUT SIGNAL AT PIN 28 & 29 OF

I601 (MSP3415)


(*MUTE : HIGH)

CHECK FM SIGNALAT PIN 58 OF I601

CHECK SIGNAL AT PIN 35 OF I501

CANCEL MUTE FUNCTION

CHECK / REPLACEI602

(TDA8944J)

CHECK VOLTAGE Vcc(13.5Vdc) AT PIN 3

(TDA8944J)


I602 (TDA8944J)



CHECK / REPLACESF02 (K9650M)

Q103, C108

CHECK / REPLACEI601

(MSP3415)

OK

ABNORMAL

NORMAL

NORMAL

ABNORMAL

NORMAL

NORMAL

ABNORMAL

NORMAL

NORMAL

NORMAL

ABNORMAL

NG

OK

NORMAL

ABNORMAL

CHECK VOLTAGE AT PIN 7, 18, 24 & 39 OF I601

CHECK WAVEFORM SDA(PIN 10) SCL(PIN 9)

XTAL(PIN 62 & 63)

CHECK SIGNALAT PIN 28 & 29

OF I501


NORMAL

ABNORMAL

ABNORMAL

ABNORMAL

26




(TRANSMITTER BOARD)


CHECK IC1(DHR-0015)


CHECK PULSEAT PIN 36 OF I701



OK

ABNORMAL

NG

NG ABNORMAL NORMAL

OK

OK

CHECK MAIN B+(143V) LINE


310Vdc AT 220V






(1S1888)R819 (10W 3.3OHM)





CHECK/REPLACE

I823 (3.3V Reg)

CHECKSDA(PIN 2)

&SCL(PIN 3)


D840 (1N4148)D830 (BYV95C)

CHECK/REPLACE

T402 F.B.T& CRT


WAVEFORM OF I501


CHECK/REPLACEI501

OK


14V & 45V LINE

ABNORMAL NORMAL

ABNORMALNORMAL


ABNORMAL NORMAL

ABNORMAL NORMAL

NORMAL ABNORMAL

NORMAL ABNORMAL

ABNORMAL

NORMAL

ABNORMAL

OK

27


1. N O RAST E R

ABNORMAL

NORMAL

(TDA9365)

28









TO WAVEFORM 1 ]





CHECK / REPLACE CRT

OK



(SF01)



ABNORMAL

ABNORMAL

ABNORMAL

ABNORMAL

ABNORMAL

NORMAL

NORMAL

NORMAL

NORMAL

ABNORMAL NORMAL

NORMAL

NORMAL

OK

29




CHECK SIGNAL ATPIN 1 & PIN 2 OF I301 [REFER

TO WAVEFORM 10 11 ]

CHECK VERTICAL Vcc 14V ATPIN 3 & 45V AT PIN 9OF I301(TDA8358J)


CHECK SIGNALAT PIN7 OF I301


D313

CHECK OUTPUTWAVEFORM AT PIN 21, PIN 22

OF I501


CHECK / REPLACECRT

CHECK / REPLACEI501

OK

ABNORMAL

ABNORMAL


NORMAL

NORMAL

NORMAL

30




I601 (MSP3415)


(*MUTE : HIGH)

CHECK FM SIGNALAT PIN58 OF I601

CHECK SIGNAL AT PIN 35 OF I501

CANCEL MUTE FUNCTION

CHECK / REPLACEI602

(TDA8946J)

CHECK VOLTAGE Vcc(13.5Vdc) AT PIN 3

(TDA8946J)


I602 (TDA8946J)



CHECK / REPLACESF02 (K9650M)

Q103, C108

CHECK / REPLACEI601

(MSP3415)

OK

ABNORMAL

NORMAL

NORMAL

ABNORMAL

NORMAL

NORMAL

ABNORMAL

NORMAL

NORMAL

NORMAL

ABNORMAL

NG

OK

NORMAL

ABNORMAL

CHECK VOLTAGE AT PIN 7, 18, 24 & 39 OF I601

CHECK WAVEFORM SDA(PIN 10) SCL(PIN 9)

XTAL(PIN 62 & 63)

CHECK SIGNALAT PIN 28 & 29

OF I501


NORMAL

ABNORMAL

ABNORMAL

ABNORMAL

31




(TRANSMITTER BOARD)


CHECK IC1(DHR-0015)


CHECK PULSEAT PIN 36 OF I701



OK

ABNORMAL

NG

NG ABNORMAL NORMAL

OK

OK

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