Ser

vice

Man

ual

- LC

D-8

412K

/S

R

LCD-8412K/S

Ser

vice

Man

ual

- LC

D-8

412K

/S

Repairing precedures for no sound, no picture and no

light.

NO

NO YES

NO YES

YES NO

YES

YES

Check whether power indicator lights in red.

YES

Check whether +5Vsupply of CPU isnormal or not.

Press POWER to check whether0~5V or 5~0V change isavailable on CPU ○,7 pin ornot.

Check whetherinput +12V and78L05 is broken ornot.

Check whether

C1815,B1203 for ON/OFF

of CPU and subsequent supply

circuit is short-circuited or not.

Check whetherexternal circuitfor key input pinand CPUP10)P11)pins are normal ornot.

Check whether each voltage for theoutput of power supply is normal or not.

Change 32K cillation

Change CPU

Change B1203 C1815.

Repair power supply andsupply circuits.

Check whetheroutput of highvoltage isavailable ornot.

Check whether highvoltage supply N25 isopen-circuited or nt.

Change audion ofhigh voltagecircuit or the highvoltage transformer.

Change LCD screen Check why N25 is open-circuited.

YES

YES

YES

NO

YES

NO NO

NO

YES

NO

��Repairing procedures for Inferior color

NO

NO

NO

NO

Check whether output voltage fromLA76810○,19○,20○,21 is normal or not.

Whether LA76810 ○,30 ○,31 pinsare short-circuited or notand whether ○,18pin is normalor not.

Check whether loop of IR3Y26�○,8○,9 and LA76810○,19○,20○,21

is normal or not.

Change the broken elements of loop.

Change module ofLCD software.

Check whetherperiphery ofIR3Y26 is normalor not.

Change IR3Y26

YES

YES

- 3 -

��WITH Sound, with light and black screen

YES

NO

Check whether power supplyof LA76810 ○,25 ○,18 pins isnormal or not.

Check whether LA76810○,13○,12

○,11pins are normal or not.

Check power supply.

Check whether linefield pulse of CPUis normal or not.

Whether the groundresistance of LA76810 ○,29

pin is normal or not.

Check the

LA76810line field

synchronous

circuit.

Whether it is okafter change CPU.

Check +5V +7.5V powersupply of IR3Y26 is normalor not.

Change the resistance.

Check if the copper sheet ofline field synchronous pulseloop is open orshort-circuited or not.

Check LCD screen and replace.

Change IR3Y26.

YES

NO

NO

YES

YES

NO

NO

NO YES

- 4 -

��Repairing Procedures for line field synchronization

NO

YES

NO

YES

YES

YES

NO

Check whether +5V +8Vpoweersupply of LA76810 is normal ornot.

Repair power supply.

Check whether peripheral circuitof LA76810 pin is normal or not.

Change 1u 333 capacitance

Check peripheral circuit of 4001IC Pcircuit for treatment ofline field synchronization).

Check the connector pin � to LCD screen is normalor not..

Change module.

Check the abnormal part.

Change LCD screen.

NO

�,repairing procedures for white light.

NO

YES

NO

NO

YES

NO

NO

YES

Test whether the switch power supply +5V +8V and

–15V are normal or not.

Whether repair power supplyand subsequent circuit isshort-circuited oroverloaded.

Test whether IR3Y26�+5V and +7.5power supply is normal or not.

Check the loop ofpower supply.

Change LCD screen.

Check the loop ofpower supply circuit.

Test whether +5V, +17V and –15V ofbus socket is normal or not.

Change module of LCD screen.

Check whetherIR3Y26 is brokenor not.

��NO SIGNAL.

YES

NO

YES

NO

YES

NO

YES

Test whether +40V is normal or not.

Check 40V loop.

Test whether wave band switch voltage is availablewith CPU ○,1○,41○,42 pin. Test � pin VT output voltageis normal or not.

Check whether AGC voltage for +5V power supply of TVtuner is normal or not. Check the TV turner VT voltageis normal or not.

Change CPU.

Change the TV tuner.

Check whether circuit of pre-centralamplifier and periphery of LA76810○,50

pin is normal or not.

Check periphery of ○,50pin forpre-central amplifier.

Check 5V power supplyand AGC circuit, andalso check the circuitof VT voltage.

NO

��Can not store program.

NO

NO

YES

Check whether 32V-tuningvoltage is normal or not.

Repair tuning loop.

Check whether AFT circuit is normal or not.

Change TV tuner and sound surface

Repair AFT circuit.

YES

- 8 -

��With picture, no or low sound and distortion

YES

NO

YES

NO

Test whether loudspeaker is opencircuited or not.

Test whether power amplifier386 is broken or not.

Change loudspeaker.

Check whether LA76810○,1○,2pins are normal or not.

Test whether poweramplifier 386 isbroken or not.

Change peripheralelements or ○,1 ○,2

pins.

Check whetherLA76810 ○,52 ○,53 ○,54 pinsare normal or not.

Change peripheral circuit of ○,52○,53○,54.

Change LA76810.

YES

NO

YES

NO

��Dark light

NO

NO

YES

NO

YES

Check whether contrastand bright are adjustedto minimum or not.

Check whether powersupply of each circuitis normal or not.

Check supply powercircuit.

Adjust potentiometer ofmain board BRI to seewhether there is change ornot.

Check whether peripheral elements of IR3Y26 are normal or not.

Adjust till OK

Change IR3Y26

Set analog quantityof TV at standard.

YES

��with picture, with sound, no character or inferior

color.

NO

NO

Check CPU 32K crystal oscillation.

Check whether pulse input ofCPU line fieldsynchronization is normal ornot.

Change 32Kcrystal oscillation.

Check whether CPU ○,22 � ○,25 toLA76810 ○,13 � ○,16 is normal ornot.

Check line fieldsynchronization circuit.

Inferior character color.

Change CPU or LA76810.

Change loop elements.

NO

YES

YES

NO

���AV no picture or no sound.

NO

NO

YES

Check whether AVconnects wire isnormal or not.

Check input socket.

Change AV connect wire

Check the loop of audio and LA76810○,51pin, andthe loop of video and LA76810○,42 pin.

Change input socket.

Change LA76810

YES

YES

���No flip vertical/horizontal function

NO

YES

Press keys on remote control.

Test CPU ○,35○,36 pins to check 1�Whether0�5V or 5�0V change is available onP15)P16) pinR 2�Whether 0�5V or5�0V change is available on ○,3○,4pinsfor picture mode selection.

Check whether CPU○,35○,36○,3○,4 tothe copper sheet of LCD module○,3 ○,4 ○,18 ○,19 pins is opencircuited or not.

Change remotecontroller and tryagain.

Change remotecontroller head.

Change LCD screen.

NO

1 2 3 4 5 6

A

B

C

D

654321

D

C

B

A

11

22

33

44

55

CF1CF38.0

FOF 1

KIF 2

4.43F 3

IDF 4

4.0F 5

R-Y 6

B-Y 7

GND 84.09

SAND10

4.4311

SYS12

KIL13

VI14

VCC(8V)15

EOU16

IC10LA7642N

AUDIO1

FM.OUT2

PIF.AGC3

RF.AGC4

IF.IN5

IF.IN6

IF.GND7

IF.VCC(5V)8

FM.FILTER9

AFT.OUT10

BUS11

BUS(L)12

ABL13

R.IN14

G.IN15

B.IN16

BLANK.IN17

RGB.VCC(8V)18

R.OUT19

G.OUT20

B.OUT21

ID22

VER.OUT23

V.RAMP.ALC24

H/BUS.VCC25

AFC.FILTER26

HOR.OUT27 FBP.IN 28

REF 29

CLK.OUT 30

I HHDL.VCC 31

CCD.FIL.TER 32

I HDL.GND 33

SECAM.IN 34

SECAM.IN 35

C AFC.FIL.TER 36

SEL.VIDED.OUT 37

X.TAL 38

C AFC.FIL.TER 39

SEL.VIDEO.OUT 40

V C DEF.GND 41

EXT.V.IN/Y.IN 42

V C DEF.VCC(5V) 43

INT.V.IN/C.IN 44

BLACK.STRECH 45

VIDEO.OUT 46

VCO.FILER 47

VCO 48

VCO 49

PIF.APC 50

EXT.AUDIO.IN 51

SIF.OUT 52

SND.APC 53

SIF.IN 54

IC7LA76810

1

2

3

4 5

6

7

8

IC9CSC386P

+5V

R4110KR426K8

C33473

C35223C37223C39

103

GNDC41103

R47100K

R48

100K R5027K

C421uF

+5V

SD

SCL

SDA

AFT

C451uF

R51100K

GND

R652K2

R67120 R68

3K3

R722K2

C47474

C46224

C48333

+5VGND

C491uFC50

100uF

AGC

C8539PC86102C871uF

C8818P

R861K

R87330

L715uH

GND

C8910uF

C9610uF

C930.47uF

C900.47uF

R88180K

R89330

C92470P

C9156PLT1

R921K5

R901K

R9722K

R91560K

R9420K

C951uF

C944u7

C970.47uF

GND

C99103

C98220P

R95

150

R961K

R932M

C10018P X2

4.433MHzC10310uF

C102103R98

1KR9910K

R100150

C129103C130103

C133103

Q11A1015

C104103

+5V

C101103

C106103

C10510uF

C10710uF

R102100

R2510K

R1041K

R1364K7

R1031K

R1054K8

GND

R1011K

C1321uF

C1351uF

C1361uFC1371uF

C1311uF

C1341uF

+8V

C1192u2

C121470uF

C123100uF

C84472

R323K3

R12022

R3510

R313K3

GND12

J7

+ -

C10847PC51

472

VO

L

RO

GO

BO

VER

HO

R

SLIRROUND1

50/602

ALAMP(16:9)3

WO.OF-VOL(4:3)4

VOLUME-L5

VOLUME-R6

POWER7

VT8

GND9

XTAL110

XTAL211

VDD(5V)12

KEY13

AFT14

SIF215

SIF116

RESET17

FILT18

CHRDMA19

V.SYNC20

Y.SYNC21 R.OUT 22

G.OUT 23

B.OUT 24

BLANK 25

IO 26

SDAO 27

SCLO 28

SDAO1 29

SCL1 30

SAFTY 31

S-VHS 32

SD 33

IR 34

U/D 35

L/R 36

MUTE 37

AV1 38

AV2 39

ENGLISH 40

BAND2 41

BAND1 42

IC1LC863324A

A0 1

A1 2

A2 3

A3 4SDA5

SCL6

TEST7

(5V)8

IC524C04

AG

C

VT

BU

BH

BL

BM

IFAN

T

TU1

TDQ-3CV1

C38103

C34104

C30100uFC1

22uFC3

10uFC31

10uFC32

10uFR40150

R39100

R434K7

R44220

R451K

R4633

ANT1

C2104

C5104C6

104

R422K

R622K

R722K

R312K

R251K

R522K

R10470R84K7

R910K

R151K2

C4680P

C7100P

R1110K

R1210K

R1310K

R1410K

R16680

R1710K

R2610K

R21330

R23270K

R694K7

R204K7

R228K2

R241K5

C36104

+33V

C40103

+8V

R4922K

R52100R53

22KR5422KR5622K

R55100

R5722K

R58100

R5922KR6122K

R60220

R6222K

R63220

R663K3

R704K7

R643K3

R714K7

X132K

C818P

C915P

1 2 3 4

J1IR C5V KEY GND

C10103

C131uF

C1422uF

Q2A1015

ZD13V9

C12103

C5V

C5V

C5V

C5V

C5V

C5V

AGC

REMOTE

Q1C1815

Q9C388A

R11K

C43104

HS

VS

+8V

+8V

+5V

BIGI

GI

BI

RI

RI

SDA

SCL

SD

+5V

REMOTE

AFT

+12V

VO

L

+5V

+8V

POWER

R341K

R3324K

+5V

FBP

BLANK

BLANK

1 2 3 4 5 6 7 8 9 10 11 12

13

14

15

16

17

18

19

20

21

22

23

24

252627282930313233343536

37

38

39

40

41

42

43

44

45

46

47

48

IC13

IR3Y26A

C147104

R157100

R158100

R159100

R15451K

R16062K

R15647K

R15533K

C148104

C149104

C158104C159104C160104C161104

R18412K

C157220uF

C151104

C152104

C150104

R1671K5

R1651K5

R1661K8

R11747K

R11647K

R11936K

R11847K

R12324K

R12147KR122

47K

R1341K

R12636K

R12456K

R12547K

R12836K

R12747K

C117104

C118104

C120104

C122104

C125104

C126104

R133100R135100

R13036K

R12947K

R13251K

R13130K

C127104

C128104

R16210K R163

10KR16410K

B RGVR25K

VB

VG

VR

ROGOBO

SYNC

FRP

PSI

+7V

5V5V

5V

R10810K

R10710K

R10618K

R1422K2

R11010K

R11310K

R10910K

R15110K

R11133K

C114102

+8V

+5V

+5V

C140102

C141

104

R1434K7

C143104

C144103 C146

103C115

103

C145103

Q12C1815

R1123K9

R1523K3 R153

3K3

R1508K2

R14910K

Q17C1815

Q14C1815

R14422K

R1454K7

VS

VER HS

SYN

C

HO

R

FBP

1

2

3

4

5 6

7

8

9

10

T1TRANS-09

C22104

C15104

C16104

C17104

C18104

C21104

Vin 1

GN

D2

Vout3

IC278L05

C23470uF

C19100uF

R3047

R2710K

R281K

Q4B1202

1 2 3 45678

IC62368

C66104

C74104

C58102

R77330K

R7827K

R826K8

R802K2

R8182K

R29180K

R75100

R8322K

R842K2

VR11K

C2010uF

C56100uF

C24470uF

L1

D8IN5819

D3IN4937

D6IN4937

D4IN5819

D5IN4937

D7IN5819

C53100uF

L4100uH

L5100uH

L6100uH

C54104

C55104

C52104

C60104

C111104

C112104

C113104

C63104

C67104

C68104

C69104

C70104

C71104

C75104

C76104

C77104

C79104

C62220uF

C59220uF

C61220uF

C6547uF/25V

C64100uF

C78100uF

C73220uF

C72220uF

C5722uF/50V

C11022uF/50V

C10922uF/50V

R7410K

R732K7

ZD317V

ZD233VC5V

Q3C1815

Q103518

POW

ER

C27104C28

104

C80104

C25

470u

F

C8327P/3KV

C291uF

+33V

+17V

+8V

+7V

-15V

5V

+5V

+12V

R7910K

R7622K

P/N16:9

4:3

R1391K

R1741K

+5VR140***

R138100

C1381uF

R14175

D9IN5819

C124104

1 2 3 4 5 6

GN

D7

8910111213

VC

C14

IC84001

1 2 3 4 5 6

GN

D7

8910111213

VC

C14

IC124001

Q13C1815

+8V

1

2

3

4

5

6 7

8

ST1U15

1

2

3

45

6

7

8

IC3T5001

1

2

3

45

6

7

8

IC4S140

L2100uH

FU1N25

Q6C1815

Q8A1015

C2610uF

L339uH

D1S41G

R361K

R852K2

R371K

R381K3

Q5DKPJ

Q7DKPJ

D2M.O

12J6

FU3U185

GND

+17V

5V

123456789101112131415161718192021222324252627282930

CON401

30PIN

-15V

PSI

FRP

5V

U/DL/R

VRVGVB

SYNC

GND

GND

GND

GND

C44103

+5V

16:9

4:3

C178102

R23012K

R23110K

U/D

R2071K3

JV-845LA

P/N

DK1

DC1

ANT2

AV1

AV2

PY3

PY4

PY2

L/R

PY1U/D

L/R

U/D

L/R

FUK1

+12V

IVIY

IVIY

CSY

PY7AUDIO

C11***

R180R

R195K6

PY5

CSY

R11447

C81102

PY6

R1154K7

R1461K5

SK1POWER

SK7CH+

C82104

R1483K9

VCC 3GND 2IR 1

IC11REMOTE

LED1

R137150K

SK2TV/AV

SK6CH-

SK3MENUV

SK5VOL+R161

4K7

R1472K7

R16927K

R1688K2

1 2 3 4

Y1IR C5V KEY GND

SK4VOL-

ANT3

PT33 SYNCPT32 IVIY

PT14 L/RPT30 U/D

PT36CSY

PT40PSI

PT31 FRP

PT37 VBPT38 VGPT39VR

PT35 4:3

PT34 16:9

PT13 P/N

PT6

PT7

PT5

PT12

PT2

PT1APC

PT3AUDIO

PT4VIDEO

PT8

PT9

PT16

PT15

PT17

PT18

PT19

PT20

PT21

PT26+33V

PT27+17V

PT29+8V

PT28+7V

PT25-15V

PT43+5V

PT245V

PT2212ViN

PT23C5V

PT10 PT11

PT42

PT41