LG CN27A24, C25A24T, C27A24T, CB27A25Z Service Manual

SECTION 6

12345678910

Interconnect Diagram

FX3402

9S4

IR1

6K2

IC1400

OUT
VCC

GND

SW1

SW4

CA Chassis Model Information

MODE L SCR CABI NET AUDIO PIP JACKS MODULE MICRO OP GUIDE

1

TX3401

QX3251

C

E

B

IC2100

C25A24T 25 TableT op
C27A24T 27 TableT op
CB27A25Z 27 TableTop

MT S/SAP None 6
MTS/SAP 1 Tuner 6 221-01387-01
MTS/SAP None 6

Component

Level

Repair

FX3401

SW6SW3SW2SW1 SW4 SW5

I

C
X
3

4
1
2

EX3401

LX3401

1

3
R

8

3
T
8

3
Y
3

3R8

QX3203

E

C

B

AC HIGH

AC LOW

DEGAUSS
DEGAUSS

HORIZO NTAL YO KE HI
HORIZO NTAL YO KE LOW
VERTICAL YOKE LOW
VERTICAL YOKE HI

ULUL

DAG GROUND

2F5

TX3204

F

G

I

+

L

R

2

A

O

1

M

5

U

E

V

N

N

D

T

221-01385-01 206-03479

206-03481

221-01385-01 206-03481

This diagram applies to

G2

the following CA models:

C25A24T
C27A24T

CB27A25Z

LEFT INT SPKR HI

LEFT INT SPKR LOW

R
K
P
S

FOCUS

LEFT SPEAKER

G

ENTER ADJ LEFT ADJ RIGHT

F

FOCUS

E

G2

D

S

F

V

V

+

+

G

G

9

G

5

S

S

N

N

V

C

N

D

V

D

D

S

L

D

A

W

C

PIPB

1

W

L

I

R

Y

N

G

A

B

P

N

M

A

I

D

P

C

P

K

1

R

G

B

F
B

+

+

+

+

R

G

B

L

U

P

U

U

N

I

P

P

P

K

P

1

PIPA

6

1

1

I

C
2
5
0
2

8

GROUND

+5VSTDEY

DATA

CLOCK

CONTROL

9

9-2107

B

SELECT

CRT1

6P2

MENU

C

TU6000

TGND

B

E

VOL DOWN VOL UP CH DOWN CH UP POWER

6K2

Q5101

C

E

B

5F2

B

C

E

1

Q5103

1

ICX2200

2

C
5

Q5102

4G9

5C2

R + UP
G + UP
B + UP

FBLNK

R
G
B

SW + PIP

GND

VIN PIP

B

G

-

-

O

O

U

U

T

T

1

+
5

I

G

K

K

E

E

R

Y

Y

O

1

U

2
N
D

KEYBOARD VARIES BY MODEL SOME HAVE FEWER KEYS, SEE MODEL BOM FOR

R

V

D

S

A

I

KEYBOARD APPLICATION SPECIFICS.

D

T

E

A

Y

2K6

+215V

GROUND
FILAMEN T

+9V

GND
R-OUT
G-OUT
B-OUT

PIPA1

1

FLYBACK

VRAMP

GND

+5 V

GND

+9 VSW

GND
SCL
SDA

R

G

-

+

O

9

N

U

V

D

T

1

D
L
2
2
0
0

IC6000

J1

12

MENU CH-UP CH-DWN VOL-UPVOL-DWN ON/OFF

SW3

SW6 SW5

SW2

IR6000

PIPB1

I

I

C

N

X
3
4

G

0
1

O
U
T

1

I

C

1

1

1
4
0
2

IC804

IC2501

JACKP AC K IS SOLD ER ED T O MA IN CHASSIS

A-18785-03

A-18785-02

OUT LOUT R

A

IN LIN RVID

Y/C

CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE LETTER “X“ IN THEIR
COMPONENT DESIGNATORS. REPLACE ONLY WITH PART NUMBERS SPECIFIED.

IN LIN RVID

RIGHT INT SPKR HI

RIGHT INT SPKR LOW

R
K
P
S

RIGHT SPEAKER

ALL SYMBOLS WITH “M” ON END OF DESIGNATOR
INDICATE SURFACE MOUNTED COMPONENT

CA SHEET 16-1

Power Supply

12345678910

G

PWRCONT

+18

CX3407
330UF
200V

VSW

0.2

Q3403

121-1340A

0.65

C

E

0

R3419

B

4.7K

1/4W

+18
VSB

W3401

Q3405

PROV

E

C

R3425M

PROV

18.70

E

R3426M

B

PROV

+18
AUD

18.40

C

B

Q3404

121-1102A

17.93

R3412M
10K

R3414

2.2K

0.029

0

C

E

Q3402

121-1340A

B

0.64

R3418

4.7K

1/4W

ICX3401

221-213-09
126-3326-02

1

3

IN OUT

2

0

+18
VSB

L3405

33UH

20-4462-18A

+18
VSW

RX3417

CX3430
470UF
25V

15
5W

CX3428

PROV

14.86

3T8

58-546-02

2

1

F

TO

DEGAUSSER

THX3415

63-10710A

KX3401

195-161

3

2

DX3405

4

1

103-347-3A

DX3400 212-172-04 (PACKAGE FOR 32/36”)

3R8

58-546-03

1

A.C.
LINE

2

3

E

FX3401

136-114-23A

EX3401
A-19238

RX3400

5.6M
1/2W

4A-250V

CX3400

0.0047UF
500V

CX3401

0.1UF
250V AC

LX3401

095-04593

4

3
1

6

DX3401, DX 3402, DX3403, DX3404 103-588A (DISCRETE FO R 25/27”)

CX3403

1000V

1000PF

D

X

3

4

0

1

CX3406

4

0

4

3

1000PF

X

D

1000V

B+
VDC

CX3402

0.0047UF
500V

CX3405

1000V

1000PF

CX3404
1000PF
1000V

RX3401

0.68
5W

2

0

4

3

X

D

DX3400

D

X

3

4

0

3

D

8.95

C3429

16V
100UF

DEG-CLT

PWRCONT

+9V

SW

DEG-CTL

S
H
E
E
T

3

RX3427

D3411

103-00589

B+

CX3420
220MFD

200V

C3421

470PF

500V

P/L

RX3423

P/L
2W

+18
VSB

CX3424
1000UF
25V

SWITCH MODE REGULATOR

RX3405

C

CX3408

470PF
500V

B

5

4

ICX3400

223-00028

126-03660-01

0.135

3

140.8

2

0.458

1

-41.79

A

CX3409
1000PF
2000V

DX3406

103-344-06A

RX3406

47

1/4W

RX3403

0.15
5W

0.133

CX3410
1000PF
500V

RX3404

180K
1/2W

B

CX3412
1000PF
500V

B+
VDC

C

E

0.45

QX3401
121-1348

0

CX3413

50V
22UF

CX3411

0.033
50V

RX3407

30
2W

RX3409

15OHM

1/2W

RX3408

10
2W

DX3407

103-344-06A

CX3416

DX3408

103-344-06A

CX3418

220PF
500V

LX3410

149-54 9

25V
100UF

B+

VDC

CX3415

1.2
1250V

3W

TX3401

095-04574

18
11

8
7

13

5

15

1
4

16

0.01

FX3402

136-00148-23C

LX3403

149-540-01

C3419

470PF
500V

149-540-01

D3410

103-589

LX3404

C3425
470UF

25V

*

IN OUT

10.82

ICX3402

221-213

123

4.96

+18
VSW

8
2
4
3
X
R

1
0

4
3
X
D
Z

+5V

SB

5
7

V
5
1

C3426
220UF

16V

W
2

/
1

A

4
2

­9
7

2

­3
0

1

W3402

E

C

C3460
220UF
25V

R3422M

PROV

Q3406

PROV

+15
VSW

D3414

+5V

TUNE

PROV

B

R3424

PROV

L3407

P/.L

This sche matic appl ies to

the following CA models:

C25A24T
C27A24T

CB27A25Z

CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE LETTER “X“ IN THEIR
COMPONENT DESIGNATORS. REPLACE ONLY WITH PART NUMBERS SPECIFIED.

ALL SYMBOLS WITH “M” ON END OF DESIGNATOR
INDICATE SURFACE MOUNTED COMPONENT

CA SHEET 26-2

Audio Processor MTS

12345678910

PWRCONT

SHT.4

SHT.4

SHT.4
SHT.4

DEG-CTL

IF
COMP-AUD

G

EXT-L

EXT-R

F

E

D

C

B

R1412

2.2K

R1413

2.2K

C1409

4.7uF

C1410

4.7uF
10V

R1405M

3.3K

R1407M

10V

C1401M

1

4.1

0.015
C1402MC1403M

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

16V

4.1

4.1

4.1

4.1

4.1

4.1

0

4.8

4.8

0

0

4.1

4.0

0

4.1

3.9

5.3

4.1

1.3

1.2

0

4.5

8.84.1

C1404M

6800pF

50V

C1416

10uF

C1436

25V

1uF
50V

R1404M

61.9K
1%

C1425

4.7uF
50V

C1430
100uF
16V

6800pF

50V

C1435M C1434M
PROV
50V

C1418

1uF
50V

C1413

10uF

50V

R1406M

100K

PROV
50V

R1425M

1M

C1421

5600pF

50V

+9V

SW

C1433M

0.01uF
25V

C1420

0.012
50V

R1421M

8.2K

R1422M
10K

R1401

100

R1402

100

C1415

R1408M

3.3K

1uF
50V

C1414

10uF

50V
10%

LOW-LEAKAGE

LOW-LEAKAGE

C1422

0.0473K
50V

C1428

4.7uF
50V

0.015
16V

C1406M C1431M

0.022

0.01

16V

25V

C1432

4.7uF
50V

R1409M

1M

C1417

10uF

25V

C1419

10%

3.3uF
50V

C1424

2700pF

50V

C1426

10uF

25V

C1427

10uF

25V

48

4.1
BASSL1

47

4.1
BASSR2

46

4.1
BASSR1

45

4.1
SURRTC

44

4.1
TVOUT-L

43

4.1
TVOUT-R

42

4.1
AUX2-L

41

4.1
AUX2-R

40

4.1
AUX1-L

39

4.1
AUX1-R

38

0.6
VLTC

37

0.7
VLDC

36

4.1
VCAWGT

35

1.7
VCATC

34

4.1
VCAIN

33

4.1
VEOUT

32

1.7
VETC

31

4.1
VEWGT

30

4.0
VE

29

4.1
SAPIN

28

4.0
SAPOUT

27

3.7
NOISETC

26

4.1
STIN

25 24

SUBOUT

IC1400

BASSL2

TRE-R

TRE-L

SURRIN

SURROUT

LSOUT-R

LSOUT-L

NC

SDA

SCL

DGND

SAD

MAININ

MAINOUT

NC

PCINT1

PCINT2

PLINT

COMPIN

VGR

IREF

GND

SAPTC

VCC

W1404

W1405

C851

10uF

50V

R1442M

1K

C1441M

0.01uF

R851M

10K

C855M

6800pF

50V

121-1310A

25V

Q1401

C861

R861M

10K

10uF

50V

*

2.2K

R862M

2.2K
*

R852M

This sche matic appl ies to

the following CA models:

C25A24T
C27A24T

CB27A25Z

+15
VSW

R1440M

C

E

10K

B

R1441M

100K

R1443M

J1402M

PROV

B

2.1

R1444M

R1445M

470

100

330

C865M

6800pF

50V

330uF
16V

5.4

C

E

1.5

C1440

Q1402

121-1310A

C1442
47uF
16V

C862

100uF

16V

R864M

150

100uF

C852

100uF

R854M

C1443

0.47uF

C843

16V

150

50V

25V

19.5

1

0.6
2

0

5

0

6

0.6

0

221-1127

R1448M

PROV

2.1

470

B

R1449M

100

R1450M

330

5.4

C

E

1.5

Q1403

121-1310A

C1445
47uF
16V

C1446

0.47uF
50V

J1450M

R1447M

1K

C1444M

0.01uF

A

Composi te Audio

D
U
A

­P

A

L

M

D

C

O

S

S

C

25V

4

R1446

680

R1451

680

R843

330

+18
AUD

0.1
50V

19.6
93

8

0

IC804

221-598-01

9.9

10

7

9.7

Q800

121-1310A

C841C842
1000uF
25V

C863

0.1
50V

R863

C853

0.1
50V

R853

19.5
C

E

0

C864

1000uF

25V

3.3

C854

1000uF

25V

3.3

B

0

58-526-04

SPEAKERS

1

2

3

4

TO_TV

VM-OUT-L

VM-OUT-R

MUTE

9S4

DEG-CTL

EXT-L

EXT-R

MUTE

AUXSWITCH1

EXT-AUD

VM-OUT-L

VM-OUT-R

SDA

SCL

COMP-AUD

SHT.6

SHT.6

SHT.6

IF

SHT.6

SHT.6

SHT.6

SHT.6

SHT.6

SHT.6

SHT.6

SHT.6

SHT.6

CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE LETTER “X“ IN THEIR
COMPONENT DESIGNATORS. REPLACE ONLY WITH PART NUMBERS SPECIFIED.

6-3 CA SHEET 3

ALL SYMBOLS WITH “M” ON END OF DESIGNATOR
INDICATE SURFACE MOUNTED COMPONENT

Main Microprocessor

12345678910

G

PWRCONT

DEG-CTL

EXT-L

EXT-R

3
T

E
E
H

F

S

IF

MUTE

E

M

M

V

V

9

0

O

1

2

O

R

0

0

R

6

6

P

P

R

AUD-SWITCH

VOL-CTRL

3
T

E
E

EXT-AUD

D

H
S

VM-OUT-L

C

B

A

VM-OUT-R

3
T

E
E
H

SDA

S

SCL

COMP-AUD

R

R6021M
PROV

M

V

2

O

2

R

0

6

P

R

R6023M
PROV

M

V

5

R6024M

O

2

PROV

0

R

6

P

R

2K6

58-526-05

1

L

2

D

A

R

N

3

A

R

O

E

B

4

T

Y

X

E

5

E

K

MUTE

CRT-PROTECTOR

C6035
PROV

50V

R6018
PROV

SW1

ON/OFF

P/L

SW2

CH-UP

P/L

SW3

CH-DOWN

P/L

SW4

VOL-UP

P/L

SW5

VOL-DOWN

P/L

SW6

MENU

P/L

L6005

020-04129-08

M

V

9

O

2
0

R

6

P

R

L6004

020-04129-08

1UH

+5V
SBF

+5V

SBF

R6017M

PROV

C6036M
1000PFD
50V

R6004M

47K

R6003M

10K

R6015

R6016

C6001M

120PF

50V

+5V

SBF

R6069M

470K

1K

1K

T
U
O
V

3

+5V
SBF

R6001M

4.7K

C

Q6001

121-1310A

E

0

R6008M

10K

C6068M

PROV

IR6000

P/L

+5V
SBF

PROV

C6009

0.10UF
50V

R6002M

220

0.4

R6026

R6080

750K

R6005M

Q6002

121-1310A

+5V
SBF

R6012M

10K

C6040M

120PF

R6033M

0

JUMPER

4.7K

B

47K

R6053M

1.5K

C6061M
47PF

50V

50V

C6037

220PF

50V

+5V
SBF

5

0

+5V
SBF

C6006

C

E

C6043M

10000

1UF
50V

C6008M
PROV

C6010M

+5V
SBF

D6002

103-461A

R6090M

+5V
SBF

R6058M
39K

R6061M

C6079M

25V

R6031M

1K

20PF

50V

WF12

3.60V
18 US

2.2K

47PF

C6042M

C6003M

4.3
B

0.1

R6070M
470K

D
N

S

G

V

1

2

R6028

C6004
PROV

WF4

2.34V
20 US

R6006M

150

1K

C6058M

47PF

50V

50V

10000

25V

470PF

50V

C6005M
220PF
50V

R6034M

WF

12

C6062M

PROV

R6027

L6007

4.7UH

20-4129-16

1M

+5V

SB

WF2

4.98V
20US

50V

2.2K

4.7UF

R6030

JUMPER

C6007M
1000PF

CRY6001

224-74-02A

C6011M
20PF
50V

L6001

4.7UH

20-4129-16

C6013

220UF

16V

47PF

C6092M

47PF

C6098

50V

R6032M

15K

50V

+5V
SBF

5.2

5.2

2.25

3.8

4.9

4.9

C6093M

63PF

C6090M

50V

4.56

0

0

50V

50V

5.14

4.9

4.85

1.44

1.44

0.16

3.42

0

0

C6012M
10000PF

25V

WF3

4.40V
5MS

IC6000

1

HSYNC

2

VSYNC

3

4

FM_SD

5

6

7

8

9

4.9
11

12

13

CRT-PROT

14

15

REMOTE

16

17

18

19

20

21

22

23

24

25

26

P/L

AFC

VERT-SIZE

N/C

HORZ-SIZE

SYNC

A/D_KEY2

A/D_KEY1

N/C

SWITCH

PIPSWITCH1

Y/C-SENSE

AUX_SW1

PIP_BRT

N/C

MUTE

N/C

N/C

AVCC

RADIO/TV

HLF

DEG-CTL

RVCO

POWER

VHOLD

CHASSIS_ID

CVIN

CNVSS

OSC-OUT

XIN

XOUT

VSS

VOL

N/C

AUD-

H/T

SCL1

SCL2

SDA1

SDA2

IDENT

RESET

OSC-IN

VCC

WF1-A
5V
2O MS

N/C

FB

4.85

WF10

5.0V
5 US

4.9

52

R

4.9

51

G

4.9

50

B

4.9

49

48

47

46

45

44

43

42

41

40

39

38

37

36

35

34

33

32

31

30

29

28

27

C6017

0.10UF
50V

4.9

2.9

R6035M

C6014M

27PF
50V

+5V
SBF

47PF 50V

47PF 50V

160PF

47PF

47PF

47PF

47PF

47PF

470PF

470PF

47PF 50V

R6036M

P/L

1M

221-1177A

47PFD
50V

C6038M

C6095M

C6053M

160PF 50V

C6052M

160PF

50V

C6051M

50V

C6094M

PROV

C6041M

50V

C6050M

50V

C6049M

50V

C6048M

50V

C6047M

50V

C6019M

50V

C6046M

50V

C6045M

L6002

020-04277-10A

R6059M

R6037M

27K

VCC OUT

IC6002

KIA7042

C6023M

UP UP UP UP

C6055M

47PF
50V

R6045M

R6046M R6047M

R6044M

330

R6043

220

R6042M

330

R6041

220

C6018M
2200PF

50V

CRY6002

C6016

2.2UF

PROV

4.7K

1UH

4.7K

GND

4.7K

WF1
5V
20 MS

C6025M

C6024M

PROV PROV PROV

R6048M

4.7K 4.7K

C6015M

27PF
50V

C6056M

10000PF
25V

D6001

103-461A

C6033M

+5V

SBF

+5V
SBF

L6003

20-4129-8

R6049

1UH

C6020

4.7UF
50V

220

R6084M

P/L

C6065M

P/L

50V

C6057M

+9V
SW

R6039M

220

R6050M

PROV

R6082M

P/L

C6067M

PROV

R6040M

P/L

R6081M

PROV

+5V

TUNE

C6030

1000MFD

16V

L6000

P/L

CX6027

PROV

OMIT FOR 175-2771 TUNER

WF5

4.88V
1 US

5

220

6
7

8

C6021M

10000PF
25V

3

IC6001

221-745-04

4

2
1

C6066

PROV

ZD6001

33V

103-279-36A

C6029M
10000PF
25V

R6072

10K

C

B

E

TP6006

+33V

C6032

1UF

50V

**ONLY FOR 175-2771 TUNER

C6026M

PROV

Q6003

P/L

C6090
PROV

C6064M

P/L

TP6005

C6031M
2200PF
50V

**J6000M

C6070
PROV

C6028

4.7UF
50V

FASTBLANK

HALFTONE

R6083M

P/L

VERT-SIZE

HORZ-SIZE

VOL-CTRL

PIPSWITCH1

AUXSWITCH1

AUXSWITCH

DEG-CTL

PWRCONT

175-2721 ZENI TH TUNER
175-2771 LG TUNER

TP6010

TP6004

+5V
SBF

VERT-SIZE

HORZ-SIZE

AUXSWITCH1

R+UP

AUD-SWITCH

G+UP

EXT-L

B+UP

EXT-R
IF
PIPSWITCH1

FM/IF-OUT
R+UP

G+UP
B+UP

FASTBLANK

IF

TU6000

11
10

9
8
7
6
5
4
3

2

1

TUNNER

FACTORY

SETUP

4G9

5

4
3

2

1

58-526-05

CRT-PROTECTOR
SCL
SDA

Y/C-SENSE
VRAMP
COMP-VIDEO
SYNC
AFC
VERT-DRIVE
FLYBACK

S
H
E
E
T

5

AGC

EXT-AUD

COMP-AUD

VM-OUT-L
VM-OUT-R

This schematic applies to
the following CA models:

C25A24T
C27A24T

CB27A25Z

S
H
E
E
T

5

CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE LETTER “X“ IN THEIR
COMPONENT DESIGNATORS. REPLACE ONLY WITH PART NUMBERS SPECIFIED.

6-4 CA SHEET 4

INDICATE SURFACE MOUNTED COMPONENT

ALL SYMBOLS WITH “M” ON END OF DESIGNATOR