LG CF-20/21S42EH User manual

MENU
POWER OK
SOUND PICTURE
VOL VOL
PR
PR
DTS
COLOR TV
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
CHASSIS : MC-84D
MODEL : CF-20/21S42EH
MODEL : CF-20/21S12EH
website:http://biz.LGservice.com
e-mail:http://www.LGEservice.com/techsup.html
Jan, 2001
Printed in KoreaP/NO : 3828VD0062G

- 2 -
CONTENTS
Contents ................................................................................................................ 2
Safety Precautions ............................................................................................3
Specifications ..................................................................................................... 4
Control Descriptions ....................................................................................... 6
Disassembly Instructions ..............................................................................9
Adjustment ...........................................................................................................10
Troubleshooting..................................................................................................14
Exploded View .................................................................................................. 16
Exploded View Parts List..............................................................................17
Replacement Parts List ............................................................................... 20
SVC. Sheet ................................................................................................................

- 3 -
SAFETY PRECAUTIONS
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by 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 manufacturer.
General Guidance
An lsolation 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 resulting in
personal injury from electrical shocks.
It will also protect the receiver and it's components from being
damaged by accidental shorts of the circuitary that may be
inadvertently introduced during the service operation.
If any fuse (or Fusible Resistor) in this TV receiver is blown,
replace it with the specified.
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 high vacuum and large surface area of picture tube,
extreme care should be used in handling the Picture Tube.
Do not lift the Picture tube by it's Neck.
X-RAY Radiation
Warning:
To determine the presence of high voltage, use an accurate
high impedance HV meter.
Adjust brightness, color, contrast controls to minimum.
Measure the high voltage.
The meter reading should indicate
23.5 ¡1.5KV: 14-19 inch, 26 ¡1.5KV: 19-21 inch,
29.0 ¡1.5KV: 25-29 inch, 30.0 ¡1.5KV: 32 inch
If the meter indication is out of tolerance, immediate service
and correction is required to prevent the possibility of
premature component failure.
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 be sure the set is safe to operate without damage of
electrical shock.
Leakage Current Cold Check(Antenna Cold Check)
With the instrument AC plug removed from AC source,
connect an electrical jumper across the two AC plug prongs.
Place the AC switch in the on positioin, connect one lead of
ohm-meter to the AC plug prongs tied together and touch other
ohm-meter lead in turn to each exposed metallic parts such as
antenna terminals, phone jacks, etc.
If the exposed metallic part has a return path to the chassis, the
measured resistance should be between 1MΩ and 5.2MΩ.
When the exposed metal has no return path to the chassis the
reading must be infinite.
An other abnormality exists that must be corrected before the
receiver is returned to the customer.
Leakage Current Hot Check (See below Figure)
Plug the AC cord directly into the AC outlet.
Do not use a line Isolation Transformer during this check.
Connect 1.5K/10watt resistor in parallel with a 0.15uF capacitor
between a known good earth ground (Water Pipe, Conduit, etc.)
and the exposed metallic parts.
Measure the AC voltage across the resistor using AC
voltmeter with 1000 ohms/volt or more sensitivity.
Reverse plug the AC cord into the AC outlet and repeat AC
voltage measurements for each esposed metallic part. Any
voltage measured must not exceed 0.75 volt RMS which is
corresponds to 0.5mA.
In case any measurement is out of the limits sepcified, there is
possibility of shock hazard and the set must be checked and
repaired before it is returned to the customer.
Leakage Current Hot Check circuit
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 the same type tube as specified in
the Replacement Parts List.
1.5 Kohm/10W
To Instrument's
exposed 
METALLIC PARTS
Good Earth Ground
such as WATER PIPE,
CONDUIT etc.
AC Volt-meter
IMPORTANT SAFETY NOTICE

- 4 -
SPECIFICATIONS
Note:Specifications and others are subject to change without notice for improvement.
No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Model No.
System
PAL-B
PAL-G
PAL-I, I/I
PAL-D
PAL-K
SECAM-B
SECAM-G
SECAM-D
SECAM-K
SECAM-K1
SECAM-I (6.0)
SECAM-L (AV)
NTSC-3.58/4.5
NTSC-3.58/5.5
NTSC-3.58/6.0
NTSC-3.58/6.5
NTSC-3.58/4.5(50)
NTSC-4.43/5.5
NTSC-4.43/6.0
NTSC-4.43/6.5
PAL 5.5/60Hz
PAL 6.0/60Hz
PAL 6.5/60Hz
SECAM 5.5/60Hz
SECAM 6.0/60Hz
SECAM 6.5/60Hz
CT-
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
26
CF-
O
O
O
O
O
O
O
O
O
O
O
O
X
O
O
O
X
O
O
O
O
O
O
O
O
O
24
CA-
O
O
X
X
X
X
X
X
X
X
X
X
X
O
X
X
X
O
X
X
O
X
X
X
X
X
5
CD-
O
O
O
O
O
X
X
X
X
X
X
X
O
O
O
O
O
O
O
O
O
O
O
X
X
X
16
CZ-
O
O
O
O
O
X
X
X
X
X
X
X
X
O
O
O
X
O
O
O
O
O
O
X
X
X
14
TOTAL SYSTEM
¡Power requirement:
AC 110-240V, 50/60Hz (Cold SMPS)
¡Tuning system:
FVS), 100 program memory
¡Sound output:
15W+15W
¡Intermediate Frequency (IF):
Vision IF ; 38.0MHz
Color IF ; 33.57MHz(PAL)
34.42MHz(NTSC)
Sound IF ; 32.5MHz (B/G)
32.0MHz(I, I/I)
31.5MHz(D/K, K1)
33.5MHz(M)
¡Power consumption :
20": 95W), 21": 100W
¡Antenna input impedance :
VHF/UHF 75ohm , Unbalanced type
¡Voice coil impedance:
8ohm
¡OSD (On Screen Display) :
Window 3D TYPE
¡ External in/output: Headphone, SCART or Phone Jack : Option
Audio-In ; 0.4Vrms¡3dB, over 10Kohm
Audio-Out ; 0.4Vrms¡3dB, below 1Kohm
Video-In/Out ; 1Vp-p¡3dB, 75ohm
R.G.B In ; 0.7Vp-p¡3dB
¡Function:
Program Surfing
Favorite Program
Real Time
Message Edit
Tuning Lock
Eye
CATV/Hyper band
Power ball game with sound
Auto Program
Manual Program
Auto Sleep
Auto Demonstration
Quick view
ACMSa(Auto channel Memory System)
PSM(Picture Status memory)-For each program
CSM(Color Status memory)
¡Child Lock:
In the Lock on state the TV can only be operated by the Remote
controller.
If any button on the front panel is pressed, "CHILD LOCK ON" is
displayed on the screen but the button's function is not performed.
To cancel of this mode, select lock off with menu button on
Remote control only.
¡Receiving System
Turbo Sound
Turbo Picture
Turbo Boosting System
Turbo Search
Turbo Eye
Recall

- 5 -
Table 1 : Receiving System (26 System)
No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Receiving System
PAL-B
PAL-G
PAL-I, I/I
PAL-D
PAL-K
SECAM-B
SECAM-G
SECAM-D
SECAM-K
SECAM-K1
NTSC-M
NTSC 4.43/5.5MHZ
NTSC 4.43/6.0MHZ
NTSC 4.43/6.5MHZ
SECAM-I (6.0MHZ)
SECAM-L (Video In)
NTSC 3.58/4.5MHZ/50HZ
PAL 5.5MHZ/60HZ
PAL 6.0MHZ/60HZ
PAL 6.5MHZ/60HZ
SECAM 5.5MHZ/60HZ
SECAM 6.0MHZ/60HZ
SECAM 6.5MHZ/60HZ
NTSC 3.58/5.5MHZ
NTSC 3.58/6.0MHZ
NTSC 3.58/6.5MHZ
Receiving Channel
VHF Band
PAL/SECAM-B : 2-12
PAL/SECAM-D : 1-12
SECAM-K1 : 2-9
NTSC-M (US) : 2-13
NTSC-M (JAPAN) : 1-12
UHF Band
PAL/SECAM-G : 21-69
PAL-I : 21-69
SECAM-K : 21-69
PAL-K : 13-56
NTSC-M (US) : 14-78
NTSC-M (JAPAN) : 13-62
Function
Reception of broadcast and
play-back for Video Tape Recorder
Play-back for special
Video Tape Recorder
Play-back for special
Video Tape/Video disk player
Play-back for special Video Tape
Recorder

- 6 -
DESCRIPTION OF CONTROLS
All the functions can be controlled with the remote control handset.
Some functions can also be adjusted with the buttons on the front
panel of the set.
Remote control handset
Before you use the remote control handset, please install the bat-
teries. See the next page.
1. POWER
switches the set on from standby or off to standby.
2. NUMBER BUTTONS
switch the set on from standby or directly select a number.
3. Q.VIEW
returns to the previously viewed programme.
4. / (Programme Up/Down)
switches the set on from standby.
selects a programme or a menu item.
scans programmes automatically.
F / G(Volume Down/Up)
adjusts the volume.
adjusts menu settings.
OK
accepts your selection or displays the current mode.
5. DUAL/*(option)
selects the language during dual language broadcast.(option)
selects the sound output.
6. ARC (Aspect Ratio Control)
changes the picture format.
7. EYE (option)
switches the Eye function on or off.
8. PSM (Picture Status Memory)
recalls your preferred picture setting.
9. MENU
selects a menu.
10. MUTE
switches the sound on or off.
5
8
2
4
7
13
6
9
0
PSMQ.VIEW
POWER
DUAL/ ARC
EYE
SOUND PICTURE
TV/AV SSM
VOL VOL
PR
PR
OK
( )
( )
M
E
N
U
M
U
T
E
DTS
1
3
2
4
7
6
5
( )
( )
10
9
8
12
11
13

- 7 -
11. SSM (Sound Status Memory) (option)
recalls your preferred sound setting.
12. TV/AV
selects TV or AV mode.
clears the menu from the screen.
13. DTS (Digital Turbo System) SOUND (option)
selects Digital sound.
DTS PICTURE (option)
selects Digital picture.
Note :
*: No function.
Battery installation
The remote control handset is powered by two AA type batteries. To
load the batteries, turn the remote control handset over and open
the battery compartment. Install two batteries as indicated by the
polarity symbols ( and ) marked inside the compartment.
Note : To avoid damage from possible battery leakage, remove the
batteries if you do not plan to use the remote control handset for an
extended period of time.
+
-
5
8
2
4
7
13
6
9
0
PSMQ.VIEW
POWER
DUAL/ ARC
EYE
SOUND PICTURE
TV/AV SSM
VOL VOL
PR
PR
OK
( )
( )
M
E
N
U
M
U
T
E
DTS
1
3
2
4
7
6
5
10
9
8
12
11
13

- 8 -
Front panel
1. MAIN POWER (vvPOWER)
switches the set on or off.
2. POWER/STANDBY INDICATOR ( rr)
illuminates brightly when the set is in standby mode.
dims when the set is switched on.
3. REMOTE CONTROL SENSOR
4. MENU
selects a menu.
5. DD/ EE(Programme Up/Down)
switches the set on from standby.
selects a programme or a menu item.
FF/ GG(Volume Down/Up)
adjusts the volume.
adjusts menu settings.
OK
accepts your selection or displays the current mode.
6. DTS (Digital Turbo System) SOUND (option)
selects Digital sound.
DTS PICTURE (option)
selects Digital picture.
7. EYE (option)
adjusts picture according to the surrounding conditions.
8. AUDIO/VIDEO IN SOCKETS (AV2) (option)
Connect the audio/video out sockets of external equipment to
these sockets.
MENU
POWER OK
SOUND PICTURE
DTS
VOL VOL
PR
PR
1 2 3 4 5 6 7
VIDEO
AV2
L/MONO RAUDIO
Side panel
8

- 9 -
Remove
Screws Speaker
Assy
Stereo Board
CPT
DISASSEMBLY INSTRUCTIONS
Important note
This set is disconnected from the power supply through the
converter transformer. An isolating transformer is necessary
for service operations on the primary side of the converter
transformer.
Back Cabinet Removal
Remove screws residing on the back cabinet and carefully
separate the back cabinet from the front cabinet..
Chassis Assy Removal
Grasp both side of Frame and pull it backward smoothly.
Speaker Assy Removal
1. Remove P601, P602 connector from Main Board.
2. Remove respective 2 screws for tweeter speaker(R, L) and
4 screws for squawker speaker(R, L) on the front cabinwet.
3. Refer ro Exploded View for disassembling woofer speaker
in the back cover.
CPT Removal
1. Pull out the CPT board from the CPT neck.
2. Place the front cabinet on soft material not to mar the front
surface or damage control knobs.
3. Remove 4 screws securing the picture tube mounting
brackets to the front cabinet.
4. Carefully separate CPT from the front cabinet.
PICTURE TUBE HANDLING CAUTION
Due to high vacuum and large surface area of picture tube, great
care must be exercised when handling picture tube. Always lift
picture tube by grasping it firmly around faceplate.
NEVER LIFT TUBE BY ITS NECK! The picture tube must not be
scratched or subjected to excessive pressure as fracture of
glass may result in an implosion of considerable violence which
can cause personal injury or property damage.

- 10 -
OSafety Precautions
1. It is safe to adjust after using insulating transformer
between the power supply line and chassis input to
prevent the risk of electric shock and protect the
instrument.
2. Never disconnect leads while the TV receiver is on.
3. Don't short any portion of circuits while power is on.
4. The adjustment must be done by the correct appliances.
But this is changeable in view of productivity.
5. Unless otherwise noted, set the line voltage to
230Vac!10%, 50Hz.
O Test Equipment required
1. RF signal generator (with pattern generator)
2. DC Power Supply
3. Multimeter (volt meter)
4. Oscilloscope
5. Color analyzer
O RF AGC (Automatic Gain Control) Adjustment
The RF AGC was aligned at the time of manufacture for
optimum performance over a wide range conditions.
Readjustment of RF AGC should not be necessary unless
unusual local conditions exist, such as ;
1) Channel interference in a CATV system.
2) Picture bending and/or color beats, which are unusually
due to excessive RF signal input when the receiver is too
close to a transmitting tower or when the receiver is
connected to an antenna distribution system where the RF
signal has been amplified. In this case, the input signal
should be attenuated (with pad or filter) to a satisfactory
level.
3) Picture noise caused by "broadcast noise" or weak signal.
If the broadcast is "clean" and the RF signal is at least
1mV (60dBu), the picture will be noise free in any area.
Adjusting RF AGC to one end of rotation will usually cause a
relatively poor signal to noise ratio;
Adjusting to the other end of rotation will usually cause a
degradation of over load capabilities resulting in color beats or
adjacent channel interference.
OScreen Voltage Adjustment
1) Tune the TV set to receive a digital pattern.
2) Press PSM (RED) button on remote controller. (standard
picture)
3) Connect the probe of oscilloscope to the RK (Red
Cathode) of CPT Board.
4) Adjust Screen Volume of FBT so that the waveform is the
same as below figure.
O Focus Adjustment
NOTE: This adjustment should be performed after warming
up for 10 minutes.
1) Tune the TV set to receive an inactive channel station.
2) Adjust the Focus control of FBT for best overall focus.
Adjustment
1. Connect RF signal (65dB!1dB) and turn on the TV.
2. Press OK buttons on TV set and Remote Controller at the
same time to get into SVC mode.
3. Press Channel UP/DOWN button on the Remote Controller
several times to find AGC ??.
4. Press Volume UP/DOWN button until the AGC Voltage is
the same as the Table below.
5. Press OK(V) button to memorize the data.
Test Point : AGC TP (J29)
Adjust : Remote Control
Test Point : RK (Red Cathode of CPT Board)
Adjust : Screen Control of FBT
Horizontal
FlyBack Time Black level
White level
GND for dc
140Vp-p
The waveform of RK(Red Cathode) of CPT Board
TUNER
AGC Voltage
6700VPF009D
2.6
! 0.5V
6700VPF003B
2.7 ! 0.5V
Test Point : Observing Display
Adjust : Focus control of FBT
ADJUSTMENT

- 11 -
ODeflection Data Adjustment (Line SVC-1)
NOTE: To enter SVC mode, press "OK" buttons on both TV set
and the Remote control at the same time.
1. Preparation for Deflection Adjustment
1) At SVC mode, press the Yellow colored button.
If the Remote Controller doesn't have the Yellow button, you
should use a Service Remote Control (105-201G) and press
SVC button.
And then, deflection data adjustment OSD (SVC1 mode) will
be displayed.
2) Press Channel UP/DOWN button for desirous function
Adjustment.
3) Press Volume UP/DOWN button to adjust the data.
2. Deflection Adjustment Procedure
1) Vertical Adjustment
Slect VS and adjust until the mechanical center of CPT and
that of screen coincides and select VA and adjust to coincide
the inner circle of screen with outer frame of CPT.
2) Horizontal Adjustment
Select HS and adjust until the mechanical center of CPT and
that of screen coincides.
3) Vertical S Correction Adjustment
Select SC and adjust until top-bottom side pincushion are
equal.
4) Press OK(V) button to memorize the data.
3. Deflection Initial Setup Data
OWhite Balance Adjustment.(LINE SVC-0)
NOTE : This adjustment should be performed after screen voltage
adjustment.
1) Tune the TV set to receive an 100% white pattern.
2) Press OK(V) buttons on TV set and remote controller at the
same time to get into SVC mode.
3) Press Channel UP/DOWN button for desirous function
adjustment.
4) Adjust VOL+ or VOL- button for GG031.
5)
Adjust VOL+ or VOL-button in each status of "Rg--"/"Bg--" for
X=281
! 8, Y=288 ! 8 with color analyzer.
6) Press OK
(V) button to memorize the adjustment data.
OHold Down check
Short J139 and ZD747 and check if the TV set turns into stand-
by.
OHOTEL TV Mode
NOTE: This mode is useful for HOTEL TV MODEL. Dealer or
HOTEL manager can use this option.
1. AFTER SELECTING HOTEL MODE, CAN NOT CHANGE
INITIAL SET UP CONDITION.
- CHANNEL PROGRAM(AUTO PROGRAM, MANUAL
PROGRAM, EDIT FUNCTION) and OSD LANGUAGE
set up condition is fixed so the HOTEL lodger cannot
change and remove initial set up data condition at his
pleasure.
This function prevents HOTEL lodger from needless
changing channel memory data and OSD language
condition.
It will be helpful for maintainning the best suitable
condition of TV SET
2. Limit MAX. VOLUME LEVEL.
- The HOTEL lodger can only use limited range of volume
level because loud TV sound can disturb other lodger's
private business.
The HOTEL manager select maximum volume level
proper for HOTEL.
3. Only Audio without Video source available through A/V
input
- When the Audio signal is fed to A/V input jack, the Audio is
available without Video.
In the previously existing Model, sound is muted if thereÕs
no Video signal.
GHOTEL mode operating guide
1) SET UP(CH.SEARCH AND EDIT) the Channel Program
2) SET UP Proper max volume level in SVC Mode.
3) SET UP HOTEL option in SVC Mode(OPTION-2).
Status
RG
GG
BG
Initial Data
32
31
27
RemarkAdjustment
R-Drive
G-Drive
B-Drive
VL
VS
VA
HS
SC
34
25
43
36
10
Status Default
34
25
43
36
10
21" LG
34
25
43
36
10
20" LG

- 12 -
OOPTION Adjustment (SVC MODE:OPTION-1,
OPTION-2)
NOTE: When the EEPROM has been replaced, the Option data
should be restored as the function of individual system
and specification.
1) Press OK buttons on both TV set and Remote Controller at
the same time to get into SVC mode.
2) Press the Yellow button several times to find OPTION-1 or
OPTION-2.
3) Input the correspond OPTION data referring to Table below
with the numeric buttons 0~9.
Table 1. OPTION 1 Function
Table 2. Specifications for OPTION-1 data
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
W/O RF 3.58(CF-, CZ-)
with RF3.58(CT-, CD-)
Single SYSTEM(CA-)
South East Asian DUAL
with RGB Input
UBB for S-MAX(MONO)
MODEL
TOOL Option
AV2
UBB
EYE
SCART
SYSTEM
Option
OPTION Data SYSTEM SCART EYE UBB AV2
Code
00
01
10
11
0
1
0
1
0
1
0
1
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
01
01
01
01
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Function Remark
BG+I+DK
BG+I+DK+M
ONLY
ONLY+DUAL
PHONO JACK (AV1)
SCART JACK (AV1)
W/O EYE
with EYE
W/O UBB
with UBB
W/O AV2 (Front)
with AV2 (Front)
OPTION Data SYSTEM SCART EYE UBB AV2
01
01
01
01
01
01
01
01
01
01
01
01
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1

- 13 -
Table 3. OPTION 2 Function
Table 4. Specifications for OPTION-2 data
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Fast Filter IF-PLL
(for excessive RF signal)
Chinese Model only
Language varies by
MICOM Part No.
for Buyer 's request
CRIKET GAME
GAME
BOOSTER
HOTEL
LANG.
CHINA
FFI
Option Code
0
1
0
1
M
E
0
1
0
1
0
1
Function Remark
Normal Condition
FFI Active
W/O Chinese NICAM
Chinese NICAM
Multi Language (M=0)
English Only (E=1)
W/O HOTEL
For HOTEL
Pack GAME
U-Com GAME
W/O BOOSTER
With BOOSTER
OPTION Data FFI CHINA LANG. HOTEL GAME BOOSTER
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
M
M
M
M
E
E
E
E
M
M
M
M
E
E
E
E
M
M
M
M
E
E
E
E
M
M
M
M
E
E
E
E
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
OPTION Data FFI CHINA LANG. HOTEL GAME BOOSTER
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
M
M
M
M
E
E
E
E
M
M
M
M
E
E
E
E
M
M
M
M
E
E
E
E
M
M
M
M
E
E
E
E
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

- 14 -
NO RASTER
CHECK +B
at D807 cathode
Is the voltage at pin37
& 12 of IC501 8V?
Check
FUSE of AC line
Check the voltage
of C806
Check the voltage
of pin4
Check pin40
of IC501(H-out)
Check Q741
collector waveform
Check T401
& each pin voltage
Is the voltage at pin37
& 12 of IC501 8V?
Check &replace
IC501
Check &replace
IC501
Check &replace
IC501
Check the in/out
of IC841
Check u-COM
pin15 low?
Check /replace
Q802 Check /replace
D806,IC803,R809
Check /replace
Fuse,DB801,IC801
Check /replace
DB801,R811
Normal Abnormal
Yes
Yes
Yes
Yes
No
No
No
No
No
No
OK
254~340V
Open
0V
TROUBLESHOOTING
NO RASTER / SOUND OK
Check the
Heater voltage of CPT
(6 -6.5Vrms)
Check
FR704, FR901
P302, & P902
Check
FBT T701
Check the
Heater pulse of FBT
T701
Check
Ik Current of
IC501, pin18
Not OK
OK Not OK
Check/Replace
CPT Board
Components
Check
IC501, ZD904
P501, & P902
OK Not OK
OK
Check
HV, Screen voltage of
CPT
Check
FBT T701
Not OK

- 15 -
NO SOUND / PICTURE OK Select correct
system in MENU
Check the waveform
of Q651 collector
Check the waveform
of pin3 of IC202
Check demodulated
signal of pin15
Check demodulated
of input pin of IC601 or 602
Check the Vcc
of IC601/602
Check / replace
Q651
Check the voltage
of IC101(logic)
Check / replace
Q653,654
NO PICTURE / NO SOUND
Is any OSD displayed?
Check receiving system in MENU
& excute Auto-program.
Yes
OK
Not OK
Check IC01 pin9,10
(V-Sync, H-Sync)
Check IC01 pin36,37
(XLC, EXLC)
& IC01
No
Go to
NO SOUND /
PICTURE OK
Does the Auto-program
operate properly.
Store in manual-program MENU
Check 5V, 33V & IIC Bus Line
of TUNER
Is the CVBS signal OK.
( IC501 pin6 )
Check R,G,B signal
at IC501 pin19,20,21
Check
5V, 33V &
IIC Bus Line
Yes
Not OK
Not OK
OK
Check / Replace
TUNER, IC501
Not OK
OK
Check / Replace
CPT Board component
Check
CVBS singal Line
& IC501
Check IC01 pin30,31,32
(R,G,B)
OK
Not OK

- 16 -
943
700
560
340
400
530
520
913
153
150
P801
170
112
320
330
122
121
550
120
310 600

EXPLODED VIEW:20/21S42EH

- 17 -
EXPLODED VIEW PARTS LIST
The components identified by mark is
critical for safety.
Replace only with part number specified.
112 2426GCA40CD 2426GDA60CB CPT SET
120 120-D38C 120-D38C SPEAKER,8 OHM 15/25W 87
121 4810V00190B 4810V00190B BRACKET,SPK(LGEIL LOCAL)
122 3550V00085B 3550V00085B COVER,SPK(LGEIL LOCAL)
150 150-D02Y 150-D02X COIL,DEGAUSSING
170 170-A01D 170-A01D LEAD SET,CPT EARTH
300 3091V00236B 3091V00227B CABINET ASSY(LGEIL LOCAL)
3091V00236F 3091V00227F CABINET ASSY
310 5020V00362A 5020V00365A BUTTON,CONTROL 6KEY
320 320-062E 320-062E SPRING,KNOB
330 5020V00363A 5020V00367A BUTTON,POWER
340 5020V00364A 5020V00366A BUTTON,CONTROL 2KEY
400 3809V00174B 3809V00174B BACK COVER ASSY (LGEIL LOCAL)
520 6871VMM678A 6871VMM678B PWB ASSY,MAIN MC-84D
6871VMM678F 6871VMM678E PWB ASSY,MAIN MC-84D IL-LGEGF
530 6871VSM250H 6871VSM250H PWB ASSY,AV-ST LGEIL ONLY
550 6871VSM535A 6871VSM535A PWB ASSY,CONT S40 FRONT CKD
560 6871VSM414A 6871VSM414A PWB ASSY,S/W TURBO,F/CKD
600 6871VSM534D 6871VSM534D PWB ASSY,SIDA AV CKD IL
700 0IGL120104A 0IGL120104A IC,CDS SENSOR MODULE(P1201-04)
913 332-057B 332-057J SCREW ASSY,HEXAGON HEAD
943 1PTF0403116 1PTF0403116 SCREW,TAP TITE D4.0 L16.0 MSWR3/FZB
P801 174-009E 174-009E CORD,POWER(W/HOLD,HOUSING,L=200,4.0
NO DESCRIPTIONS
PART NO
20" 21"

- 18 -
913 510
112
153
170
150
511
400
943
121
104
300
700
310
320
330
120
520
530
P801
EXPLODED VIEW:20/21S12EH

- 19 -
EXPLODED VIEW PARTS LIST
The components identified by mark is
critical for safety.
Replace only with part number specified.
104 343-B52A 343-B52A SUPPORTER,PCB
112 2426GCA40CD 2426GCA60CB CPT SET
120 120-D38F 120-D38F SPEAKER,C131P01-044K14 8 OHM
121 4810V00071B 4810V00071B BRACKET,COVER (SPK)
150 150-D02Y 150-D02X COIL,DEGAUSSING
170 170-A01D 170-A01D LEAD SET,CPT EARTH
300 3091V00119B 3091V00119B CABINET ASSY
310 5020V00209A 5020V00208A BUTTON,CONTROL 6KEY
320 320-062H 320-070G SPRING,COIL
330 5020V00211A 5020V00210A BUTTON,POWER
400 3809V00085A 3809V00085A BACK COVER ASSY
520 6871VMM678C 6871VMM678D PWB ASSY,MAIN
530 6871VSM250H 6871VSM250H PWB ASSY,AV-ST LGEIL ONLY
700 0IGL120104A 0IGL120104A IC,CDS SENSOR MODULE(P1201-04)
913 332-057B 332-057J SCREW ASSY,HEXAGON HEAD
943 1PTF0403116 1PTF0403116 SCREW,TAP TITE D4.0 L16.0
P801 174-009E 174-009E CORD,POWER(W/HOLD,HOUSING,L=200,4.0
NO DESCRIPTIONS
PART NO
20" 21"

REPLACEMENT PARTS LIST
LOCA. NO PART NO DESCRIPTION
ZD90
ZD101
ZD102
ZD501
ZD502
ZD503
ZD602
ZD651
ZD741
ZD742
ZD901
ZD902
ZD903
ZD904
Q01
Q02
Q102
Q501
Q505
Q506
Q511
Q512
Q514
Q651
Q653
Q654
Q741
Q742
Q801
Q802
C02
C03
C04
C05
C07
C08
C09
C10
C11
C12
C13
C15
C18
C19
C20
0DZ910009AJ
0DZ510009AB
0DZ330009BA
0DZ180009AG
0DZ510009AB
0DZ510009AB
0DZ910009AJ
0DZ120009AF
0DZ820009AH
0DZ820009AH
0DZ750009AG
0DZ750009AG
0DZ750009AG
0DZ750009AG
0TR945009AA
0TR102009AB
0TR319709AB
0TR733009AA
0TR733009AA
0TR733009AA
0TR733009AA
0TR945009AA
0TR102009AB
0TR945009AA
0TR945009AA
0TR945009AA
0TR249900AA
0TR322809AA
0TR102009AB
0TR102009AB
0CE475DK618
0CN2220F569
0CN1030F679
0CN1030F679
0CN1010K519
0CN1010K519
0CN1010K519
181-007E
0CE106DF618
0CE335DK618
0CN1020K519
0CN1010K519
0CX1000K409
0CN1030F679
0CE107DD618
DIODE,ZENER MTZJ9.1B TP ROHM-K DO34
DIODE,ZENER MTZ5.1B,TP(52MM),ROHM
DIODE,ZENER HZT33(TP) HITACHI
DIODE,ZENER MTZJ18B TP ROHM-K DO34
DIODE,ZENER MTZ5.1B,TP(52MM),ROHM
DIODE,ZENER MTZ5.1B,TP(52MM),ROHM
DIODE,ZENER MTZJ9.1B TP ROHM-K DO34 0.5W 9
DIODE,ZENER MTZJ12B TP ROHM-K DO34 500MW 1
DIODE,ZENER MTZJ8.2B TP ROHM-K DO34 500MW
DIODE,ZENER MTZJ8.2B TP ROHM-K DO34 500MW
DIODE,ZENER MTZJ7.5B TP ROHM-K DO34 0.5W 7
DIODE,ZENER MTZJ7.5B TP ROHM-K DO34 0.5W 7
DIODE,ZENER MTZJ7.5B TP ROHM-K DO34 0.5W 7
DIODE,ZENER MTZJ7.5B TP ROHM-K DO34 0.5W 7
TR,KSC945C-Y TP SAMSUNG
TR,KRC102M,TP(KRC1202),KEC
TR,KTC3197,TP(KTC388A),KEC
TR,KSA733C-Y TP SAMSUNG TO-92
TR,KSA733C-Y TP SAMSUNG TO-92
TR,KSA733C-Y TP SAMSUNG TO-92
TR,KSA733C-Y TP SAMSUNG TO-92
TR,KSC945C-Y TP SAMSUNG
TR,KRC102M,TP(KRC1202),KEC
TR,KSC945C-Y TP SAMSUNG
TR,KSC945C-Y TP SAMSUNG
TR,KSC945C-Y TP SAMSUNG
TR,2SD2499 TO-3P(H)IS TOSHIBA
TR,KTC3228-0 TP(KTC2383),KEC
TR,KRC102M,TP(KRC1202),KEC
TR,KRC102M,TP(KRC1202),KEC
4.7UF STD 50V 20% FL TP 5
2200P 16V K X TA52
10000P 16V M Y TA52
10000P 16V M Y TA52
100P 50V K B TA52
100P 50V K B TA52
100P 50V K B TA52
MPE ECQ-V1H184JL3(TR)50V 0.1
10UF STD 16V M FL TP5
3.3UF STD 50V 20% FL TP 5
1000P 50V K B TA52
100P 50V K B TA52
10P 50V J SL TA52
10000P 16V M Y TA52
100UF STD 10V M FL TP5
LOCA. NO PART NO DESCRIPTION
IC01
Ò
ICS01
IC02
IC03
IC04
IC202
IC301
IC501
IC601
IC602
IC801
IC802
IC803
IC804
IC840
IC841
IC901
PG01
D01
D101
D401
D501
D502
D503
D504
D509
D741
D742
D743
D802
D803
D804
D805
D806
D807
D808
D901
D902
D903
D904
DB801
LD01
ZD01
ZD02
0ICTMHY007A
0ICTMHY008A
0ISG742900A
0IAL241600B
0IFA754207A
0ISA722200A
0ISG405200B
0IPH835150A
0IPH884212A
0ISG729700A
0IFA754207A
0ILI817000G
0ITF435000A
0ISK665413A
0ISK115000A
0ISS780500J
0ISS780800H
0IPH610700A
0IZZVF0017B
0DD414809ED
0DD414809ED
0DD150009CA
0DD414809ED
0DD414809ED
0DD414809ED
0DD414809ED
0DD414809ED
0DR149379AA
0DD150009CA
0DR149379AA
0DD100009AM
0DD414809ED
0DD120000BB
0DD200009AC
0DD100009AM
0DD300009AC
0DD200009AF
0DR140049AC
0DR210009AC
0DR210009AC
0DR210009AC
0DD260000BD
0DD000000BA
0DZ510009AB
0DZ510009AB
IC,GMS81C4040-TC021 HYUNDAI 52SDI
IC,GMS81C4040-TC023
IC,TDA7429 42P,SDIP BK DIGITAL CO
IC,AT24C16-10PC 8D EEPROM 16K
IC,KA75420ZTA(KA7542ZTA) 3P,TO-9
IC,LA7222(1280 AUDIO)
IC,HCF4052BE 16P,DIP BK DIFF-4CH
IC,TDA8351/N6 9P,SIP BK V/OUT(W/O
IC,TDA8842(S1)/N2 56P,SDIP BK MUL
IC,TDA7297 15P,SIP BK 2CH 15W DUA
IC,KA75420ZTA(KA7542ZTA) 3P,TO-92
IC,LTV817M-VB 4P,DIP BK PHOTO COU
IC,4N35(G)V 6D PHOTO COUPLER
IC,STR-F6654(LF1352) 5P,SIP BK ST
IC,SE115N(LF12) 3P 115V ERROR AMP
IC,KA78L05AZ TO-92 TP 5V REGULATO
IC,KA78R08 4P,TO-220F BK LOW DROP
IC,TDA6107Q SIP9 BK VIDEO OUT AMP
IC,DRAWING SEIN BK GAME MODULE
DIODE,1N4148 TA
DIODE,1N4148 TA
DIODE,RECTIFIER RGP15J,TP(52MM)
DIODE,1N4148 TA
DIODE,1N4148 TA
DIODE,1N4148 TA
DIODE,1N4148 TA
DIODE,1N4148 TA
DIODE,RECTIFIER 1N4937G TP
DIODE,RECTIFIER RGP15J,TP(52MM)
DIODE,RECTIFIER 1N4937G TP
DIODE,RECTIFIER EU1ZV(1) TP
DIODE,1N4148 TA
DIODE,RECTIFIER FML-G12S
DIODE,RECTIFIER RG2 V(1)
DIODE,RECTIFIER EU1ZV(1)
DIODE,RECTIFIER RU3AMV(1)
DIODE,RECTIFIER RU2M V(1)
DIODE,RECTIFIER 1N4004A T-81
DIODE,RECTIFIER BAV21 TP
DIODE,RECTIFIER BAV21 TP
DIODE,RECTIFIER BAV21 TP
DIODE,BRIDGE D2SBA60
DIODE,RECTIFIER LAMP
DIODE,ZENER MTZ5.1B,TP(52MM),ROHM
DIODE,ZENER MTZ5.1B,TP(52MM),ROHM
IC
TRANSISTOR
The components identified by mark is
critical for safety.
Replace only with part number specified.
DIODE
CAPACITOR
For Capacitor & Resistors,
the charactors at 2nd and 3rd
digit in the P/No. means as
follows;
CC, CX, CK, CN : Ceramic
CQ : Polyestor
CE : Electrolytic
RD : Carbon Film
RS : Metal Oxide Film
RN : Metal Film
RF : Fusible
-20 -