LG KF-20P31, KF-21P31 Service Manual

TVCR

SERVICE MANUAL

CAUTION

BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

CHASSIS : MV-025A

MODEL : KF-20/21P31

website:http://biz.LGservice.com

e-mail:http://www.LGEservice.com/techsup.html

SERVICE MANUAL MODEL:KF-20/21P31

LG Electronics inc.

CHASSIS : MV-025A

MODEL : KF-20/21P31

MODEL

CONTENT

SPECIFICATION ................................................1-2

SAFETY INSTRUCTIONS ............................ 1-3

SERVICING PRECAUTIONS ....................... 1-4

DESCRIPTION OF CONTROLS .................. 1-6

SECTION 1 SUMMARY

TVCR SERVICE MANUAL

1-2

SPECIFICATIONS

Video

Video Signal Processing System ....................................................................................................................................................................................................................PAL/SECAM

/NTSC 4.43(VCR playback only)

Video Recording System .........................................................................................................................................................................2 Rotary head helical scanning system

Head ...........................................................................................................................................................................................................................................................................................Two heads

Tape Speed .......................................................................................................................................................................................................................................................................................SP/LP

Tape Format ..............................................................................................................................................................................................................................................................VHS, width 1/2"

Timer Program ...............................................................................................................................................................................1Year, 5 programs, Normal/Daily/Weekly REC

Tape Loading System ..............................................................................................................................................................................................................................................Front loading

Input/Output Signal Level .............................................................................................................................................................................................................1Vp-p, 75Ω unbalanced

Audio

Audio Recording System .....................................................................................................................................................................................................................................................Normal

Input/Output Signal Level .............................................................................................................................................Input (0.5Vrms, 10KΩ↑), Output (0.5Vrms, 1KΩ↓)

General

Power Source ....................................................................................................................................................................................................................................................AC230V, 50/60Hz

Power Consumption ............................................................................................................................................................................................................................................. ...........20” : 100W

21” : 110W

Channel Capability ...............................................................................................................................................................................................VHF: 2-12, UHF: 21-69, CATV: S1-S20

Tuning System .............................................................................................................................................................................................................................................Voltage Synthesizer

Antenna ..................................................................................................................................................................................................................................................................UHF/VHF (75 ohm)

Sound Output ..............................................................................................................................................................................................................................3Wmax. at 50KHz deviation

Operating Condition ..........................................................................................................................................................................................................5°C

~35°C, less than 80% RH

ABBREVIATIONS : Used in this book

ADJ ............................................................................................Adjustment or Adjust

AFC ......................................................................Automatic Frequency Control

AGC ......................................................................................Automatic Gain Control

AMP ........................................................................................................................Amplifier

CPT................................................................................................... Color Picture Tube

DEF ........................................................................................................................Deflection

DET ...........................................................................................................................Detector

FBT ..............................................................................................Flyback Transformer

H.V ....................................................................................................................High Voltage

OSC ........................................................................................................................Oscillator

SEP .........................................................................................................................Separator

SYNC ......................................................................................................Synchronization

S.I.F .......................................................................Sound Intermediate Frequency

V.I.F .......................................................................Video Intermediate Frequency

H ...............................................................................................................................Horizontal

V ....................................................................................................................................Vertical

IC ...........................................................................................................Integrated Circuit

OSD ..................................................................................................On-Screen Display

SAP ........................................................................................Second Audio Program

BPF ...........................................................................................................Band Pass Filter

ST ....................................................................................................................................Stereo

LPF ............................................................................................................Low Pass Filter

DP ........................................................................................................Differential Phase

DG ........................................................................................................Differential Group

PLL.................................................................................................. Phase Locked Loop

APC ..................................................................................Automatic Phase Control

BM ...............................................................................................................................B+ Main

BT ............................................................................................................................B+ Tuning

1-3

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

0.15uF

1-4

CAUTION: Before servicing receivers covered by this service manual and its supplements and addenda, read and follow the

SAFETY PRECAUTIONS on page 3 of this publication. NOTE: If unforeseen circumstances create conflict between the

following servicing precautions and any of the safety precautions on page 3 of this publication, always follow the safety precautions. Remember: Safety First.

General Servicing Precautions

1. Always unplug the receiver AC power cord from the AC power source before; a. Removing or reinstalling any component, circuit board

module or any other receiver assembly.

b. Disconnecting or reconnecting any receiver electrical plug

or other electrical connection.

Connecting a test substitute in parallel with an electrolytic capacitor in the receiver. CAUTION: A wrong part substitution or incorrect polarity installation of electrolytic capacitors may result in an explosion hazard.

d. Discharging the picture tube anode.

2. Test high voltage only by measuring it with an appropriate high voltage meter or other voltage measuring device (DVM, FETVOM, etc) equipped with a suitable high voltage probe. Do not test high voltage by "drawing an arc".

3. Discharge the picture tube anode only by (a) first connecting one end of an insulated clip lead to the degaussing or kine aquadag grounding system shield at the point where the picture tube socket ground lead is connected, and then (b) touch the other end of the insulated clip lead to the picture tube anode button, using an insulating handle to avoid personal contact with high voltage.

4. Do not spray chemicals on or near this receiver or any of its assemblies.

5. Unless specified otherwise in this service manual, clean electrical contacts only by applying the following mixture to the contacts with a pipe cleaner, cotton-tipped stick or comparable nonabrasive applicator; 10% (by volume) Acetone and 90% (by volume) isopropyl alcohol (90%-99% strength) CAUTION: This is a flammable mixture. Unless specified otherwise in this service manual, lubrication of contacts in not required.

6. Do not defeat any plug/socket B+ voltage interlocks with which receivers covered by this service manual might be equipped.

7. Do not apply AC power to this instrument and/or any of its electrical assemblies unless all solid-state device heat sinks are correctly installed.

8. Always connect the test receiver ground lead to the receiver chassis ground before connecting the test receiver positive lead. Always remove the test receiver ground lead last.

9. Use with this receiver only the test fixtures specified in this

service manual.

CAUTION: Do not connect the test fixture ground strap to any heatsink in this receiver.

Electrostatically Sensitive (ES) Devices

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called Electrostatically Sensitive (ES) Devices. Examples of typical ES devices are integrated circuits and some fieldeffect transistors and semicounductor "chip" components. The

following techniques should be used to help reduce the incidence of component damage caused by static by static electricity.

1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any electostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging wrist strap device, which should be removed to prevent potential shock reasons prior to applying power to the unit under test.

2. After removing an electrical assembly equipped with ES devices, place the assembly on a conductive surface such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.

3. Use only a grounded-tip soldering iron to solder or unsolder ES devices.

4. Use only an anti-static type solder removal device. Some solder removal devices not classified as "anti-static" can generate electrical charges sufficent to demage ES devices.

5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ES devices.

6. Do not remove a repalcement ES device from its protective package until immediately before you are ready to install it. (Most replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil or comparable conductive material).

7. Immediately before removing the protective material from the ieads of a replacement ES device, touch the protective material to the chassis or circuit assembly into which the device will be installed. CAUTION:Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.

8. Minimize bodily motions when handling unpackaged replacement ES devices. (Otherwise harmless motion such as the bruching together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static electricity sufficient to damage an ES device.)

General Soldering Guidelines

1. Use a grounded-tip, low-wattage soldering iron and appropriate tip size and shape that will maintan tip temperature within the range or 500°F to 600°F.

2. Use an appropriate gauge of RMA resin-core solder composed of 60 parts tin/40 parts lead.

3. Keep the soldering iron tip clean and well tinned.

4. Thorohly clean the surfaces to be soldered. Use a mall wirebristle (0.5 inch, or 1.25cm) brush with a metal handle. Do not use freon-propelled spray-on cleaners.

5. Use the following unsoldering technique a. Allow the soldering iron tip to reach normal temperature.

(500°F to 600°F)

b. Heat the component lead until the solder melts. c. Quickly draw the melted solder with an anti-static,

suction-type solder removal device or with solder braid. CAUTION: Work quickly to avoid overheating the circuiboard printed foil.

6. Use the following soldering technique. a. Allow the soldering iron tip to reach a normal

temperature (500°F to 600°F)

b. First, hold the soldering iron tip and solder the strand

against the component lead until the solder melts.

SERVICING PRECAUTIONS

1-5

c. Qulckly move the soldering iron tip to the junction of the

component lead and the printed circuit foil, and hold it there only until the solder flows onto and around both the component lead and the foil. CAUTION: Work quickly to avoid overheating the circuit board printed foil.

d. Closely inspect the solder area and remove any excess

or splashed solder with a small wire-bristle brush.

IC Remove/Replacement

Some chassis circuit boards have slotted holes (oblong) through which the IC leads are inserted and then bent flat against the circuit foil. When holes are the slotted type, the following technique should be used to remove and replace the IC. When working with boards using the familiar round hole, use the standard technique as outlined in parapraphs 5 and 6 above.

Removal

1. Desolder and straighten each IC lead in one operation by gently prying up on the lead with the soldering iron tip as the solder melts.

2. Draw away the melted solder with an anti-static suctiontype solder removal device (or with solder braid) before removing the IC.

Replacement

1. Carefully insert the replacement IC in the circuit boare.

2. Carefully bend each IC lead against the circuit foil pad and solder it.

3. Clean the soldered areas with a small wire-bristle brush. (It is not necessary to reapply acrylic coating to the areas).

"Small-Signal" Discrete Transistor Removal/Replacement

1. Remove the defective transistor by clipping its leads as close as possible to the component body.

2. Bend into a "U" shape the end of each of three leads remaining on the circuit board.

3. Bend into a "U" shape the replacement transistor leads.

4. Connect the replacement transistor leads to the corresponding leads extending from the circuit board and crimp the "U" with long nose pliers to insure metal to metal contact then solder each connection.

Power Output, Transistor Device Removal/Replacement

1. Heat and remove all solder from around the transistor leads.

2. Remove the heatsink mounting screw (if so equipped).

3. Carefully remove the transistor from the heat sink of the circuit board.

4. Insert new transistor in the circuit board.

5. Solder each transistor lead, and clip off excess lead.

6. Replace heatsink.

Diode Removal/Replacement

1. Remove defective diode by clipping its leads as close as possible to diode body.

2. Bend the two remaining leads perpendicula y to the circuit board.

3. Observing diode polarity, wrap each lead of the new diode around the corresponding lead on the circuit board.

4. Securely crimp each connection and solder it.

5. Inspect (on the circuit board copper side) the solder joints of the two "original" leads. If they are not shiny, reheat them and if necessary, apply additional solder.

Fuse and Conventional Resistor

Removal/Replacement

1. Clip each fuse or resistor lead at top of the circuit board hollow stake.

2. Securely crimp the leads of replacement component around notch at stake top.

3. Solder the connections. CAUTION: Maintain original spacing between the replaced component and adjacent components and the circuit board to prevent excessive component temperatures.

Circuit Board Foil Repair

Excessive heat applied to the copper foil of any printed circuit board will weaken the adhesive that bonds the foil to the circuit board causing the foil to separate from or "lift-off" the board. The following guidelines and procedures should be followed whenever this condition is encountered.

At IC Connections

To repair a defective copper pattern at IC connections use the following procedure to install a jumper wire on the copper pattern side of the circuit board. (Use this technique only on IC connections).

1. Carefully remove the damaged copper pattern with a sharp knife. (Remove only as much copper as absolutely necessary).

2. carefully scratch away the solder resist and acrylic coating (if used) from the end of the remaining copper pattern.

3. Bend a small "U" in one end of a small gauge jumper wire and carefully crimp it around the IC pin. Solder the IC connection.

4. Route the jumper wire along the path of the out-away copper pattern and let it overlap the previously scraped end of the good copper pattern. Solder the overlapped area and clip off any excess jumper wire.

At Other Connections

Use the following technique to repair the defective copper pattern at connections other than IC Pins. This technique involoves the installation of a jumper wire on the component side of the circuit board.

1. Remove the defective copper pattern with a sharp knife. Remove at least 1/4 inch of copper, to ensure that a hazardous condition will not exist if the jumper wire opens.

2. Trace along the copper pattern from both sides of the pattern break and locate the nearest component that is directly connected to the affected copper pattern.

3. Connect insulated 20-gauge jumper wire from the lead of the nearest component on one side of the pattern break to the lead of the nearest component on the other side. Carefully crimp and solder the connections. CAUTION: Be sure the insulated jumper wire is dressed so the it does not touch components or sharp edges.

1-6

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 batteries. See the next page.

1. r-I (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. MUTE

switches the sound on or off.

4. TIMER PROG

displays the timer programme recording menu.

5. CLEAR/RESET

resets the tape counter or clears a data in the Timer

programme

menu.

(PROGRAMME UP/DOWN)

switches the set on from standby. selects a programme or a menu item.

F/G

(VOLUME UP/DOWN)

adjusts the volume. adjusts menu settings.

8. REW (REWIND/REVIEW)

rewinds the tape at high speed in the stop mode. reviews fast the tape during playback.

9. PLAY

plays back the tape at normal speed.

10. PAUSE/STILL

stops the tape temporarily during recording. displays a still picture during playback.

11. STOP

stops the tape during playback or recording.

12. SLEEP

sets the sleep timer.

13. TRK AUTO, +/-

adjust the picture automatically or manually during playback.

14. CLOCK/COUNT

displays the current time or tape counter.

15. SP/LP

selects a recording tape speed SP or LP.

16. TELETEXT BUTTONS (option)

These buttons are used for teletext. For further details, see the ‘Teletext’ section.

VOL

PLAY

P/STILL STOP

REC/ITR

REW/

FF/

SLEEP

AUTO

CLOCK/COUNT

TRK

SYSTEM Q.VIEW

SP/LP

TEXT

MUTE

TV/AV

CLEAR/RESETTIMER PROG

EJECT

5 6

7 8

12 13

(With TELETEXT)

1-7

17. EJECT

ejects the tape.

18. TV/AV

selects a TV or AV mode.

19. MENU

selects a menu.

20. OK

accepts your selection or displays the current mode.

21. FF (FAST FORWARD/CUE)

winds the tape forward at high speed in the stop mode. fast forward playback.

22. REC/ITR

starts a manual recording or instant timer recording.

23. SYSTEM

selects the desired VCR colour system.

24. QUICK VIEW

returns to the previously viewed programme.

Battery installation

The remote control handset is powered by two AA type batteries. Gently pull down the cover of the remote control handset until the battery compartment is exposed. 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.

VOL

PLAY

P/STILL STOP

REC/ITR

REW/

FF/

SLEEP

AUTO

CLOCK/COUNT

TRK

SYSTEM Q.VIEW

SP/LP

MUTE

TV/AV

CLEAR/RESETTIMER PROG

EJECT

5 6

7 8

12 13

14 15

(Without TELETEXT)

1-8

1. MAIN POWER (ON/OFF)

switches the set on or off.

Note : One power line lives even when the main power is off.

2. POWER (r-I) switches the set on from standby or off to standby.

3. REMOTE CONTROL SENSOR

4. AUDIO/VIDEO IN SOCKETS (AV2)

Connect the audio/video out sockets of the external VCR to these sockets.

5. REC/ITR

starts a manual recording or instant timer recording.

6. PLAY

plays back the tape at normal speed.

7. PAUSE/STILL (option)

stops the tape temporarily during recording. displays a still picture during playback.

8. MENU (option)

selects a menu.

9. STANDBY INDICATOR

illuminates red brightly when the set is in standby mode. dims red when the set is switched on.

10. TIMER REC INDICATOR

illuminates red when the timer programme is set for recording.

11. VOLUME UP/DOWN

adjusts the volume. adjusts menu settings.

12. PROGRAMME UP/DOWN

switches the set on from standby. selects a programme or a menu item.

13. CASSETTE COMPARTMENT

To insert a video cassette tape here.

14. REC/ITR INDICATOR

illuminates red during recording.

15. REW (REWIND/REVIEW)

rewinds the tape at high speed in the stop mode. reviews fast the tape during playback.

16. FF (FAST FORWARD/CUE)

winds the tape forward at high speed in the stop mode. fast forward playback.

17. STOP/EJECT

stops the tape during playback or recording or ejects the tape.

18. OK (option)

accepts your selection or displays the current mode.

19. TAPE-IN INDICATOR (option)

illuminates green while a video cassette tape is inserted.

20. HEADPHONE SOCKET (option)

connect the headphone plug to this socket.

Note : In some models, you might drop the set if you move it only with the handle on the top of the set. So you can should support the bottom of the set at the same time.

Front panel

REC/ITR REW/

PLAY

FF/ P/STILL STOP/EJECT OKMENU

STAND-BYTAPE-IN TIMER REC

AV2

VOL VOL

VIDEO- IN -AUDIO

ON/OFF

REC/ITR REW/

PLAY

FF/ P/STILL STOP/EJECT OKMENU

STAND-BYTAPE-IN TIMER REC

AV2

VOL VOL

VIDEO- IN -AUDIO

ON/OFF

REC/iTR REW/

PLAY

FF/

P/STILL

STOP/EJECT

VOL

STAND-BY

TAPE-IN

TMER REC

ON/OFF

AV2

VIDEO- IN -AUDIO

13 15 16 17

19 20

3 5 6 7 8910 11

2 4

AV2

ON/OFF

VOL

REC/IT R REW/ PLAY FF/ P/STILLSTOP/EJECT MENU OK

VIDEO- IN -AUDIO

STAND-BY TAPE-INTIMER REC

;

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;;;;;;;;

;

;;;;;

;

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;;;;;;;;;;

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;

;;;

;;;;;

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;;;;;;;;

;;;

;;;;;

;

;;;

;

13 15 16 17

1918

3 5 6 7 8

10 11

2 4

ON/OFF

VOL PR

STOP/EJECT REW/

PLAY FF/

REC/ITR

AV2

AUDIO

VIDEO

H/P

REC TIMER-REC STAND-BY

13 15 16

10 43

17 6 5

ON/OFF

VOL PR

STOP/EJECT REW/

PLAY FF/

REC/ITR

REC TIMER-REC STAND-BY

13 15 16

103

17 6 5

9 20

13 15 16 17

1918

3 5 6 7 8

10 11

2 4

13 15 16 17

1918

3 5 6 7 8910 11

2 4

ON/OFF

VOL

STOP/EJECT

REC/ITR

-B

ON/OFF

VOL

STOP/EJECT

REC/ITR

-B

2 17 15 6 16 5 3 14 10 9

11 12

CHASSIS : MV-025A

MODEL : KF-20/21P31

MODEL

CONTENT

EXPLODED VIEW .............................................2-2

EXPLODED VIEW PARTS LIST ..................2-3

DISASSEMBLY INSTRUCTIONS

..................2-4

SECTION 2 DISASSEMBLY PART

TVCR SERVICE MANUAL

2-2

EXPLODED VIEW

330

320

315

603

610

601

602

A00

501

520

174

913

510

112

153

170

150

310

943

400

120

2-3

112 2426GCA40CP 2426GDA80AV CPT SET

- 2426GDA80CS CPT SET A51QAE320X 00A7ND LGEAP 120 120-D44D 120-D44D SPEAKER,GENERAL C071P06K1452 16 OHM 3W/5 150 150-D02M 150-D02N COIL,DEGAUSSING 153 6150Z-1014A 6150Z-1023A DY

- 6150Z-1024A DY 170 170-A01F 170-A01F CPT EARTH 174 6410VEH004A 6410VEH004A POWER CORD HARNESSINDO VDE/SEMKO 2

174-219A 174-219A POWER CORD

300 3091V00268D 3091V00269D CABINET ASSEMBLY,W/SECAM LG

- 3091V00269K CABINET ASSEMBLY,LGEAP 310 5020V00401B 5020V00399B BUTTON 315 3580V00014S 3580V00014S DOOR,CST, W/SECAM

3580V00014Y 3580V00014Y DOOR,CST, W/O SECAM 320 320-075B 320-075B SPRING,KNOB 330 5020V00402A 5020V00400A BUTTON 400 3809V00195D 3809V00195D BACK COVER ASSY #LOCAL LGEIN PHONE

- 3809V00195H BACK COVER ASSY CKD 40AF

501 4810V00206B 4810V00206B BRACKET,SMPS

- 4810V00206A BRACKET,SMPS 520 6871VDM125N 6871VDM125E PWB ASSY,DEFLECTION MAIN2(025A) 21”,WIDE,CKD 601 4810V00195C 4810V00195A BRACKET,MAIN (P10/P10/P30), 33DECK 602 4814V00158B 4814V00158B SHIELD BOTTOM (P10/P20/P30) ,CKD 603 4814V00157F 4814V00157F SHIELD TOP CASE(20/21”), PAL ONLY, 610 6871VMMA81P 6871VMMA81E PWB ASSY,MAIN(025A) KF,W/0 TXT,PHONE,C

- 6871VMMA81L PWB ASSY,MAIN(025A) KF,W/0 TXT 913 332-057B 332-057B SCREW ASSY,HEXAGON HEAD 943 1PTF0403116 1PTF0403116 SCREW,TAP TITE(P) D4.0 L16.0 A00 6721R-0105A 6721R-0105A DECK ASSEMBLY,VIDEO D33 (2HD, NP, VCR)

LOCA. NO

20” 21”

PART NO

DESCRIPTIONS

EXPLODED VIEW PARTS LIST

The components identified by mark is critical for safety. Replace only with part number specified.

DISASSEMBLY INSTRUCTIONS

2-4

1. Back Cover Removal

Remove the screws residing on the back cover and carefully separate the back cover from the front cabinet and P/cord holder barcket.(Refer to Fig. 2-1, 2-2)

2. Main 2 PCB Removal

Grasp both sides of the support frame and pull it back and up.

3. Main Chassis Removal

1) Remove 2 screws securing the Main chassis to the front cabinet.

2) Grasp both sides of the chassis and pull it back

4. Speaker Assembly Removal

1) Remove the connector between the speaker and the main chassis.

2) To remove the speaker, remove the screw.

5. CPT REMOVAL

1) After removal of VCR chassis and speaker assy, remove the CPT board from CPT neck.

2) Plase the cabinet with the front down on suitable cushion.

3) Remove 4 screws swcuring the CPT to the cabinet.

4) Carefully separate CPT from front cabinet.

PICTURE TUBE HANDLING CAUTION

Due to high vacuum and large surface area of picture tube, great care is needed when handling the picture tube. Always lift the picture tube by grasping it firmly around faceplate. NEVER LIFT THE TUBE BY ITS NECK. The picture tube must not be scrated or subject to excessive pressure as gracture of the glass may result in an implosion of considerable violence which can cause personal injury or property damage.

Fig. 2-1

Fig. 2-2

CPT Board

Remove

Screws

Main 2 PCB

Main chassis

Speaker

CHASSIS : MV-025A

MODEL : KF-20/21P31

MODEL

CONTENT

PURITY & CONVERGENCE ADJUSTMENT

........3-2

ADJUSTMENT INSTRUCTIONS .................3-5

BLOCK DIAGRAM .............................................3-9

WIRING DIAGRAM ........................................ 3-10

TROUBLESHOOTING CHARTS .................3-11

PRINTED CIRCUIT BOARDS .......................3-16

COMPONENT LOCATION GUIDE .............3-17

SECTION 3 ELECTRICAL PART

TVCR SERVICE MANUAL

3-2

PURITY & CONVERGENCE ADJUSTMENT

Caution:

Convergence and Purity have been factory aligned. Do not attempt to tamper with these alignments. However, the effects of adjacent receiver components, or replacement of picture tube or deflection yoke may require the need to readjust purity any convergence.

● Purity Adjustment

This procedure DOES NOT apply to bonded yoke and picture tube assemblies. The instrument should be at room temperature (60 degrees F or above) for six (6) hours and be operating at low beam current (dark background) for approximately 20 to 30 minutes before performing purity adjustments.

CAUTION: Do not remove any trim magnets that may be

attached to the bell of the picture tube.

1. Remove the AC power and disconnect the internal degaussing coil.

2. Remove the yoke from the neck of the picture tube.

3. If the yoke has the tape version beam bender, remove it and replace it with a adjustable type beam bender (follow the instructions provided with the new beam bender)

4. Replace the yoke on the picture tube neck, temporarily remove the three (3) rubber wedges from the bell of the picture tube and then slide the yoke completely forward.

5. Reconnect the internal degaussing coil.

6. Position the beam bender locking rings at the 9 o'clock position and the other three pairs of tabs (2,4 and 6 pole magnets) at the 12 o'clock position.

7. Perform the following steps, in the order given, to prepare the receiver for the purity adjustment procedure.

a. Face the receiver in the "magnetic north" direction.

b. Externally degauss the receiver screen with the television

power turned off.

c. Turn the television on for approximately 10 seconds to

perform internal degaussing and then turn the TV off.

d. Unplug the internal degaussing coil. This allows the

thermistor to cool down while you are performing the purity adjustment. DO NOT MOVE THE RECEIVER FROM ITS "MAGNETIC NORTH" POSITION.

e. Turn the receiver on and obtain a red raster by increasing

the red bias control (CW) and decreasing the bias controls for the remaining two colors (CCW).

f. Attach two round magnets on the picture tube screen at 3

o'clock and 9 o'clock positions, approximately one (1) inch from the edge of the mask (use double-sided tape).

DEFLECTION YOKE

PURITY &CONVERGENCE MAGNET ASSEMBLY

RUBBER WEDGES

GLASS CLOTH TAPE

PURITY MAGNET

6-POLE

4-POLE

4-POLE MAGNET

CONVERGENCE MAGNET ASSEMBLY

6-POLE MAGNES

PURITY MAGNET(2-POLE)

X-AXIS YOKE POSITIONING (L/R PURITY)

6-POLE MAGNETS

CONVERGENCE MAGNET ASSEMBLY

3-3

8. Referring to above, perform the following two steps: a. Adjust the yoke Z-axis to obtain equal blue circles. b. Adjust the appropriate beam bender tabs to obtain correct

purity (four equal circles).

9. After correct purity is set, tighten the yoke clamp screw and

remove the two screen magnets.

10. Remove the AC power and rotate the receiver 180 degrees

(facing "magnetic south").

11. Reconnect the internal degaussing coil.

12. Turn the receiver on for 10 seconds (make sure the receiver

came on) to perform internal degaussing, and then turn the receiver off.

13. Unplug the internal degaussing coil.

14. Turn on the receiver and check the purity by holding one (1)

round magnet at the 3 o'clock and a second round magnet at 9 o'clock position. If purity is not satisfactory, repeat steps 8 through 14.

15. Turn off the receiver and reconnect the internal degaussing

coil.

● Convergence Adjustment

Caution: This procedure DOES NOT apply to bonded yoke and

picture tube assemblies. Do not use screen magnets during this adjustment procedure. Use of screen magnets will cause an incorrect display.

1. Remove AC power and disconnect the internal degaussing

coil.

2. Apply AC Power and set the brightness to the Picture Reset

condition. Set the Color control to minimum.

3. Apply 8V to the pin.

4. Adjust the Red, Green and Blue Bias controls to get a dim

white line.

5. Remove the AC power and 8V from the pin.

6. Reconnect the internal degaussing coil and apply AC power.

7. Turn the receiver on for 10 seconds to perform internal degaussing and then turn the receiver off again.

8. Unplug the internal degaussing-coil.

9. Turn on the receiver, connect a signal generator to the VHF antenna terminal and apply a crosshatch signal.

Caution: During the convergence adjustment procedure, be

very careful not to disturb the purity adjustment tabs are accidentally move, purity should be confirmed before proceeding with the convergence adjustments.

Note:

Make sure the focus is set correctly on this instrument

before proceeding with the following adjustment.

10. Converge the red and blue vertical lines to the green vertical line at the center of the screen by performing the following steps (below TABLE). a. Carefully rotate both tabs of the 4-pole ring magnet

simultaneously in opposite directions from the 12 o'clock position to converge the red and blue vertical lines.

b. Carefully rotate both tabs of the 6-pole ring magnet

simultaneously in opposite directions form the 12 o'clock position to converge the red and blue (now purple) vertical lines with the green vertical line.

11. Converge the red and blue horizontal with the green line at the center of the screen by performing the following steps. (below TABLE)

a. Carefully rotate both tabs of the 4-pole ring magnet

simultaneously in the same direction (keep the spacing between the two tabs the same) to converge the red and blue horizontal lines.

b. Carefully rotate both tabs of the 6-pole ring magnet

simultaneously in same direction (keep the spacing between the two tabs the same) to converge the red and blue (now purple) horizontal lines with the green horizontal line.

c. Secure the tabs previsouly adjusted by locking them in

place with the locking tabs on the beam bender.

MAGNETS

RED RED

1.ADJUST YOKE Z-AXIS FIRST TO GET EQUAL BLUE COLOR CIRCLES

2 .ADJUST BEAM BENDER 2 POLE MAGNET TO GET FOUR EQUAL COLOR CIRCLES

3-4

RING PAIRS

POLE

ROTATION DIRECTION

OF BOTH TABS

OPPOSITE

SAME

OPPOSITE

SAME

MOVEMENT OF RED

AND BLUE BEAMS

BR BR

POLE

12. While watching the 6 o'clock positions on the screen, rock the front of the yoke in a vertical (up/down) direction to converge the red and blue vertical lines. (Fig upper left)

13. Temporarily place a rubber wedge at the 12 o'clock position to hold the vertical position or the yoke.

14.

Check the 3 o'clock and 9 o'clock areas to confirm that the red and blue horizontal lines are converged. If the lines are not converged, slightly offset the vertical tilt of the yoke (move the rubber wedge if necessary) to equally balance the convergence error of the horizontal lines at 3 o'clock and 9 o'clock and the vertical lines at 6 o'clock and 12 o'clock.

15. Place a 1.5 inch piece of glass tape over the rubber foot at the rear of the 12 o'clock wedge.

16. While watching the 6 o'clock and 12 o'clock areas of the screen, rock the front of the yoke in the horizontal (left to right) motion to converge the red and blue horizontal lines. (Fig. upper right)

17. Temporarily place a rubber wedge at the 5 o'clock and 7 o'clock positions to hold the horizontal position of the yoke.

18. Check the 3 o'clock and 9 o'clock areas to confirm that the red and blue vertical lines are converged. If the lines are not converged, slightly offset the horizontal tilt of the yoke (move the temporary rubber wedges if necessary) to equally balance the convergence error of the horizontal lines at 6 o'clock and 12 o'clock and the vertical lines at 3 o'clock and 9 o'clock.

19. Using a round magnet confirm purity at the center, right and left sides and corners. See Purity Adjustment Procedure.

20. Reconfirm convergence and apply a 1.5 inch piece of glass tape over the rubber foot at the rear of the 5 o'clock and the 7 o'clock wedges.

RED

BLUE

RED BLUE

BLUE

RED

GREEN

BLUE RED

GREEN

ADJUSTMENT

VIEWING

AREA

UP/DOWN ROCKING OF THE YOKE CAUSES OPPOSITE ROTATION OF RED AND BLUE RASTERS

ADJUSTMENT

VIEWING

AREA

RED

GREEN

TV SCREEN

LEET/RIGHT ROCKING OF THE YOKE CAUSES OPPOSITE SIZE CHANGE OF THE RED AND BLUE RASTERS

UP/DOWN ROCKING OF THE YOKE CAUSES OPPOSITE ROTATION OF RED AND BLUE RASTERS

LEFT/RIGHT ROCKING OF THE YOKE CAUSES OPPOSITE SIZE CHANGE OF THE RED AND BLUE RASTERS

3-5

ADJUSTMENT INSTRUCTIONS

1. APPLICATION RANGE

This specification is applicable to tvcr°Øs (mv-025chassis) manufactured in the tv factory Or the approved site.

1.1 MAIN PRUDUCTION FORM

-. SET ( O )

-. SKD ( O )

-. CKD ( 0 )

2. DESIGNATION

2.1. Hot GND & Cold GND must be connected separately to prevent electric shock and to protect equipments because this chassis is an insulation chassis.

2.2. The adjustment must be done by the exact sequence.

But, it can be changeable within the allowable margin of error

2.3. Adjust surrounding condition: unless otherwise noted, adjust to the following condition

Surrouding Temperature: 25 °… °æ 5 °…

Reality Humidity : 60 % °æ 20 %

Embedded Component Body Temperature In PCB: 2

5 °… °æ 5

°…

2.4. The AC line voltage of TV must be maintained at 230V(200~250) @50/60 Hz

2.5. Before any adjustment, TV set must have warming time for 20 minutes

2.6. Necessary instrument

- Multimeter (ADJUSTMENT/ASSEMBLY Line) Max Input Current : over 1A / Max Input Voltage : 500Vdc Measurement Range : 10Vdc °≠ 100Vdc / Accuracy : 0.03%

- Oscilloscope : (ADJUSTMENT/ASSEMBLY Line)

Frequency Band : over 20ß÷ /Input Impedance : OVER

1ß

Input Capacitance : below 30pF / Max Input Voltage : 250V

- 10:1 PROBE

2.7. SIGNAL Unless otherwise noted,INPUT THE STANDARD COLOR SIGNAL 60°≠ 80 dBu. The standard color signal is LG°Øs standard digital signal. It refers the standard color signal to LG standard signal. If LG standard signal is a criterion,PAL standard signal is PALB/G 05 CH and SECAM standard signal is SECAM 04CH or 40CH. LG standard color signal has priority to others and other vendors which use different equipment from LG can use the PHILIPS DIGITAL PATTERN or COLOR BAR PATTERN or CIRCLE PATTERN depend on itmes.

3. DECK LINE ADJ.

(VCR DECK/CIRCUIT ADJ.)

3.1. P2/P3 TEMPORARY ADJUSTMENT

3.1.1. Necessary Instruments

1. PAL SP Normal TAPE

2. OSCILLOSCOPE

3. 10:1 PROBE two

4. SPECIAL NUT DRIVER (P2/P3 FOR ADJUSTMENT)

3.1.2. ADJUSTMENT

1. Play the PAL SP NORMAL TAPE

2. Connect the oscilloscope(CH-1) to J123(H/SW) of main PCB

3. Connect the oscilloscope(CH-2) to J158(RF) of main PCB

4. With observing the RF envelope waveform, adjust P2, P3 until it becomes the waveform C

5. Check the envelope waveform is in the maximum size by pressing the TRK UP(+), down(-) button

3.2. CTL/AUDIO LEVEL ADJUSTMENT

3.2.1. Necessary Instruments

1. CTL TAPE

2. PAL SP Normal TAPE(AUDIO LEVEL FOR ADJUSTMNENT)

3. OSCILLOSCOPE

4. 10:1 PROBE TWO PIECES

5. RMS METER(AUDIO LEVEL FOR ADJUSTMENT)

3.2.2 CTL ADJUSTMENT

THIS ADJUSTMENT MUST BE DONE WHEN THE UNCONTROLLED DECK IS WAREHOUSED.

1. Connect the oscilloscope to J101(CTL)

ADJUST PART LOCATION

TAKE-UP

REEL

AZIMUTH ADJUST SCEW X- DISTANT FIX SCREW

HEIGHT ADJUST SCREW

TILT ADJUST SCREW

CAPSTAN

T/UP ARM

X-DISTANT ADJUST GROOVE

PINCH- ROLLER

SUPPLY

REEL

DRUM

FE HEAD

TENTION ARM

ADJUST PART LOCATION

TAKE-UP

REEL

AZIMUTH ADJUST SCEW X- DISTANT FIX SCREW

HEIGHT ADJUST SCREW

TILT ADJUST SCREW

CAPSTAN

T/UP ARM

X-DISTANT ADJUST GROOVE

PINCH- ROLLER

SUPPLY

REEL

DRUM

FE HEAD

TENTION ARM

TAKE-UP

REEL

AZIMUTH ADJUST SCEW X- DISTANT FIX SCREW

HEIGHT ADJUST SCREW

TILT ADJUST SCREW

CAPSTAN

T/UP ARM

X-DISTANT ADJUST GROOVE

PINCH- ROLLER

SUPPLY

REEL

DRUM

FE HEAD

TENTION ARM

<A> P2 POST ADJUSTMENT

<B> P3 POST ADJUSTMENT

<C> FINAL ADJUSTMENT WAVWFORM

P2P2

<A> P2 POST ADJUSTMENT

<B> P3 POST ADJUSTMENT

FIGURE 2> P2/P3 ADJUSTMENT WAVEFORM

<C> FINAL ADJUSTMENT WAVWFORM

3-6

2. After playing the CTL control tape, make sure the CTL waveform range is from 1.5 :1 to 2.5 : 1. If it is out of range , adjust CTL waveform to the following procedures. A. If is over 2.5 :1, lower the head height.

After turning the height adjust screw counter-clockwise to adjust its level from 1.5 : 1 to 2 : 1. Check the tape location at P4. Readjust the TILT.(2:1)

B. If is under 1.5:1, heighten the head height.

After turning the height, adjust the screw clockwise to adjust its level from 2 : 1 to 2.5 : 1. Check the tape location of P4. Readjust the TILT.(2:1)

3. Play the standard tape and adjust very carefully the azimuth screw right and left by using the oscilloscope and levelmeter to maximize the audio sound. Adjust the azimuth screw & the height adjust screw at the same time because they have mutual relationship. (Check CTL again after the adjustment) *A/C head adjustment order

Height adjust screw°Êcheck the TILT°Êazimuth screw°Êcheck CTL

3.2.3 AUDIO LEVEL CHECKING AND ADJUSTMENT

1. Connect °∞+°± terminal of RMS meter (auto level meter) to J108 on the main PCB Audio output and °∞_°± terminal to GND.

2. Check that if audio level of RMS meter satisfies with the spec,If audio sound is weak, adjust the A/C head azimuth screw.

3. Audio level spec

1K :0.5 °æ 0.1Vrms 6K :1KHz °æ 1.5dB

3.3. X-DISTANT/P2,P3 ADJUSTMENT

3.3.1. NECESSARY INSTRUMENT

1. SP PAL TAPE

2. OSCILLOSCOPE

3. 10:1 PROBE : 2 PIECES

4.SPEACIAL DRIVER FOR ADJUSTMENT(P2,P3,XDISTANT(NUT),AUDIO(NUT))

5. RMS METER(AUDIO LEVEL METER)

3.3.2. ADJUSTMENT PREPARATION

1.Connect oscilloscope(CH-1) to J123(H/SW) on main PCB.

(Use for trigger of CH-2 )

2.Connect oscilloscope(CH-2) to J158(RF) on main PCB.

(Use waveform of CH-2)

3. Play by inserting SP PAL TAPE (2hd:normal tape)

4. After the picture is appeared, make initial condition by pressing the tracking adjustment up(+) button of the remote controller.

3.3.3. X-DISTANCE ADJUSTMENT

1. Turn the X-distant adjust groove of the deck right and left to maximize the scope waveform.

2. Check that if waveform satisfies with the linearity by pressing TRK Up(+) and Down(-) button

3. Tighten the X-distant adjust screw.

3.3.4. P2/P3(RF LINEARITY) CHECK & ADJUSTMENT

1. Adjust p2 & p3 so that the the RF envelope waveform of the oscilloscope becomes C in figure 2.

2. Check if the envelope waveform becomes maximum by pressing TRK Up(+),Down(-) button onestep.

3.4 PG ADJUSTMENT

Adjust it after finishing controlling the Deck.

3.4.1.NECESSARY INSTRUMENT

1. SP PAL TAPE

2. OSCILLOSCOPE

3. 10 : 1 PROBE 2 PIECES

3.4.2. ADJUSTMENT

1. Insert and play the SP PAL TAPE

2. Connect the oscilloscope(CH-1) to H/SW(J123) on the main PCB and trigger in setting the VOL/DIV to 1V range.

3. Connect the oscilloscope(CH-2) to video out(J173) on the main PCB and set the VOL/DIV to 500mV range.

4. Set the TIME/DIV of oscilloscope to 50us range.

5. Adjust the falling edge(412us °æ 20us) of vertical sync in the video signal by varying VR01.

4.ASSEMBLY LINE ADJUSTMENT

4.1. RF AGC ADJ.( APPLYING THE W/S TUNER )

4.1.1. NECESSARY INSTRUMENT : DIGITAL MULTIMETER

4.1.2. ADJUSTMENT PREPARATION

1. HEAT-RUN at least 15 minutes before adjustment.

2. Input the PAL DIGITAL PATTERN(EU05); The intensity of electric field for the applied tuner refers to the below data.

3. Connect the DIGITAL MULTIMETER to TP-AGC(J335) of MAIN1.

4.1.3. ADJUSTMENT

1. Press the SVC key of the transmitter and select °∞AGC°±of

the SVC MENU using PR+/- key.

2. Adjust it by the below data varying VOL+/- key.

4.2. FOCUS ADJUSTMENT

4.2.1. Receive the standard color signal.

CTL WAVEFORM

ADJUST PERIOD (6.5H = 412us)

PG ADJUST WAVEFORM

*CAUTION: SET THE TRIGGER MODE OF OSCILLOSCOPE TO DC

ADJUST PERIOD (6.5H = 412us)

PG ADJUST WAVEFORM

*CAUTION: SET THE TRIGGER MODE OF OSCILLOSCOPE TO DC

TUNER

6700VPF009V

6700VMF001H 6700VPF009Q

Electric fields strenth

AGC Voltage

70dBu

±0.2dBu

2.7±0.05Vdc

AGC not adjust.

SETTING & ADJUSTMENT

4.2.2. Let the picture be the most clear by the criterion of the vertical line of it, varying the focus V/R of FBT.

4.3. PURITY AND CONVERGENCE ADJUSTMENT

: Warm up the TV set at least 15 minutes before adjustment.

4.3.1. PURITY ADJUSTMENT

1. After degaussing the CPT with using the degaussing coil, set the picture at Standard ON.

2. Receive the raster signal or E50CH(red pattern) from a pattern generator.

3. Move the DY toward CPT PANEL to put the picture like the figure 5.

4. Turn the purity magnet(the second pole magnet) to let red color located at the center of picture. At the same time let color-line located at the center vertically.

5. After finishing the second pole magnet adjustment, fix it temporarily by the lock ring.

6. Let the picture became uniform red color by moving the DY

slowly backward and then tighten the fixing screw. (Check the slope)

4.4. SCREEN ELECTRIC VOLTAGE

1. ONPUT PAL DIGITAL PATTERN(EU05 CH)

2. SELECT CHANNEL 0

3. CONNECT THE PROBE OF OSCILLOSCOPE TO THE RK OF CPT PCB

4. SET the oscilloscope TO 50V/DIV, 20us/DIV(using 10:1 Prpbe ) and after putting the GND ling upon the lowest grid

line of the scope by pushing the GND button, enter into DC mode.

* Adjust screen volume of FBT so that the waveform is the same

as below figure.

4.5 WHITE BALANCE

4.5.1 NECESSARY INSTRUMENT

: WHITE BALANCE METER

4.5.2 ADJUST PREPARATION

1. Adjust it after warming up the meter over 15 minutes.

2. Input the picture with the white signal and black signal at upper and lower side each in a standard of the CPT°Øs horizontal center.

3. Set this picture in the status of standard ON.

4.5.3 ADJUSTMENT

: Push the SVC key of a transmitter which is possible to control

the SVC and adjust the RG and BG varying the VOL +/-, in the status of the initial data 32 of the CG in SVC MENU on the screen. (This chassis adjusts only the high light.)

4.6. DEFLECTION DATA ADJUSTMENT

4.6.1. INPUT PAL DIGITAL PATTERN(EU05CH)

4.6.2. PRESS SVC KEY ON THE SERVICE REMOTE CONTROLLER AND SELECT LINE SERVICE2 MODE ADJUSTABLE ITEM IS SELECTED BY CH+/- KEY,

VARIABLE ITEM IS SELECTED BY VOL +/- KEY.

4.6.3. DEFLECTION EARLY ESTABLISHMENT DATA

4.6.4.VERTICAL SLOPE, V-SLP ADJUSTMENT

: Select V-SLP mode and adjust until horizontal center line of the large circle coincides with blanking line

4.6.5. VERTICAL AMPLITUDE, V-AMP ADJUSTMENT

: Select V-AMP mode , and adjust until the upper and lower end of the large circle reach 5ßÆ inside from the effective area of CPT.

4.6.6. VERTIVAL SHIFT, V-SFT ADJUSTMENT

: Select V-SFT mode and adjust until the horizontal center coincides with the vertical sign Slot mark of CPT.

4.6.7. HORIZONTAL SHIFT, H-SFT ADJUSTMENT

: Select H-SFT mode and adjust until the vertical center coincides with horizontal sign slot mark of CPT.

4.6.8. VERTICAL S-CORRECTION, S-COL ADJUSTMENT

: Select S-COL mode and adjust until the grid of cross hatch

R BG

< figure 5 >

PICTURE STANDARD ON

CONTRAST : 85%

BRIGHTNESS : 70%

COLOUR : 50%

140V

BLACK LEVEL(DC)

GND

140V

BLACK LEVEL(DC)

GND

1 2

140V ± 3V 130V ± 3V

Adjust Voltage Remark Note

Model(14/20/21)

NON-EU

9000K

10000K

288 281

295 288

X Y Color Temperature

Model(15 FLAT )

NON-EU

9000K

12000K

288 272

295 288

X Y Color Temperature

STATUS

V-SLP

V-AMP

V-SFT H-SFT

S-COL

Vertical Slope

Vertical Amplitude

Vertical Shift

Horizontal Shift

Vertical S-correction

25 31 32 32 15

Adjust Cintents YYYY

3-7

pattern is even all over the screen.

4.7. CDL DATA ADJUSTMENT

1. INPUT PAL DIGITAL PATTERN(EU05CH).

2. PRESS SVC KEY ON THE SERVICE and SELECT LINE SERVICE1 MODE Adjustable item is selected by CH+/- key,variable item is

selected by VOL +/- key

3. INITIAL ESTABLISHMENT DATA

* 2nd SIF OPTION

4.8. LANGUAGE

STATUS

AGC

GG RG BG

PEAK

CDL

2nd SIF

RF Gain

Green Drive Gain

Red Drive Gain Blue Drive Gain Peaking Control

Cathode Drive Level

2nd SIF

15 32 32 32 17 10

15 32 32 32 17 08

15 32 32 32 17 12

CONTENTS 15”21” 20” 14”

Mode

0 1 2

OFF

BG DK

INternal BPF

BG : EXTERNAL DK/I:INTERNAL BPF

DK: EXTERNAL BG/I:INTERNAL BPF

Funtion Remark Note

1 2 3 4

FRANCE

GERMANY

Other EU

Except EU

FRENCH GERMAN ENGLISH ENGLISH

If buyer request

special language we

can accept it.

Country

Language

Remark Note

3-8

3-9

BLOCK DIAGRAM

UOC TDA9361/81

(VCD,TXT)

TUNER

MICOM

SECAM

DECODER

TA1238N

Y/C

LA71590M

DYDY

DRUM

AUDIO AMP

OSD IC

RGB

CRT

SPEAKER

CVBS

AUDIO IN

CONTROL

REC

RF AUDI O OUT

VCR

CVBSI N

VCR,AV AUDIO IN

CVBS IN

CVBS

OUT

RF CVBS

VCR OUT

AV CVBS IN

AV AUDIO IN

AV AUDIO OUT

3-10

WIRING DIAGRAM

TOUCH .

P805

P708

P602

P804

P03

P01

P02

P708

P602

P805

P804

P708

P102

P702

P703

P901A

SMPS PWB

P802

P103

P100

CPT PWB

3-11

Is there about 6V at pin 9 of P804?

YES

Is there about 11V

at '+' terminal

of C856?

YES

Is there about 6.1V

at pin 9 of IC801?

YES

Is there voltage at

pin 9 of T801?

YES

NO POWER : NO STAND-BY

Replace the Fuse

Check the 6V Line of MAIN 1 BOARD

Check if the

Fuse is O.K.?

YES

Check/Replace

DB801, R801, C806.

Check/Replace

D806, Q801, R807, ZD801, C814,

IC801.

● Check/Replace FR851, D852,

C856, Q860, Q861, Q862, ZD860, ZD861, R874.

● Check the pin 11 of P804 :

'LOW"

Check/Replace

IC857, D856, F852, C875

TROUBLE SHOOTING

+ 56 hidden pages

LG KF-20P31, KF-21P31 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual