LG KF-20P31 User 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 layback only)
Video Recording System .........................................................................................................................................................................2 Rotary head helical scanning system
Head ...........................................................................................................................................................................................................................................................................................Two heads
Ta e S eed .......................................................................................................................................................................................................................................................................................SP/LP
Ta e Format ..............................................................................................................................................................................................................................................................VHS, width 1/2"
Timer Program ...............................................................................................................................................................................1Year, 5 rograms, Normal/Daily/Weekly REC
Ta e Loading System ..............................................................................................................................................................................................................................................Front loading
In ut/Out ut Signal Level .............................................................................................................................................................................................................1V - , 75Ω unbalanced
Audio
Audio Recording System .....................................................................................................................................................................................................................................................Normal
Head ..................................................................................................................................................................................................................................................................................Normal(MONO)
In ut/Out ut Signal Level .............................................................................................................................................In ut (0.5Vrms, 10KΩ↑), Out ut (0.5Vrms, 1KΩ↓)
General
Power Source ....................................................................................................................................................................................................................................................AC230V, 50/60Hz
Power Consum tion ........................................................................................................................................................................................................................................................20” : 100W
21” : 110W
Channel Ca ability ...............................................................................................................................................................................................VHF: 2-12, UHF: 21-69, CATV: S1-S20
Tuning System .............................................................................................................................................................................................................................................Voltage Synthesizer
Antenna ..................................................................................................................................................................................................................................................................UHF/VHF (75 ohm)
Sound Out ut ..............................................................................................................................................................................................................................3Wmax. at 50KHz deviation
O erating 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 ........................................................................................................................Am lifier
CPT................................................................................................... Color Picture Tube
DEF ........................................................................................................................Deflection
DET ...........................................................................................................................Detector
FBT ..............................................................................................Flyback Transformer
H.V ....................................................................................................................High Voltage
OSC ........................................................................................................................Oscillator
SEP .........................................................................................................................Se arator
SYNC ......................................................................................................Synchronization
S.I.F .......................................................................Sound Intermediate Frequency
V.I.F .......................................................................Video Intermediate Frequency
H ...............................................................................................................................Horizontal
V ....................................................................................................................................Vertical
IC ...........................................................................................................Integrated Circuit
OSD ..................................................................................................On-Screen Dis lay
SAP ........................................................................................Second Audio Program
BPF ...........................................................................................................Band Pass Filter
ST ....................................................................................................................................Stereo
LPF ............................................................................................................Low Pass Filter
DP ........................................................................................................Differential Phase
DG ........................................................................................................Differential Grou
PLL.................................................................................................. Phase Locked Loo
APC ..................................................................................Automatic Phase Control
BM ...............................................................................................................................B+ Main
BT ............................................................................................................................B+ Tuning

1-3
SAFETY PRECAUTIONS
Many electrical and mechanical arts in this chassis have s ecial safety-related characteristics. These arts are identified by in
the Schematic Diagram and Re lacement Parts List.
It is essential that these s ecial safety arts should be re laced with the same com onents as recommended in this manual to
revent X-RADIATION, Shock, Fire, or other Hazards.
Do not modify the original design without ermission of manufacturer.
General G idance
An lsolation Transformer sho ld always be sed during
the servicing of a receiver whose chassis is not isolated from
the AC ower line. Use a transformer of adequate ower rating
as this rotects the technician from accidents resulting in
ersonal injury from electrical shocks.
It will also rotect the receiver and it's com onents from being
damaged by accidental shorts of the circuitary that may be
inadvertently introduced during the service o eration.
If any fuse (or Fusible Resistor) in this TV receiver is blown,
re lace it with the s ecified.
When re lacing a high wattage resistor (Oxide Metal Film
Resistor, over 1W), kee the resistor 10mm away from PCB.
Kee wires away from high voltage or high tem erature arts.
Due to high vacuum and large surface area of icture tube,
extreme care should be used in handling the Pict re T be.
Do not lift the Picture tube by it's Neck.
X-RAY Radiation
Warning:
To determine the resence of high voltage, use an accurate
high im edance 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 revent the ossibility of
remature com onent failure.
Before ret rning the receiver to the c stomer,
always erform an AC leakage c rrent check on the ex osed
metallic arts of the cabinet, such as antennas, terminals, etc.,
to be sure the set is safe to o erate without damage of
electrical shock.
Leakage C rrent Cold Check(Antenna Cold Check)
With the instrument AC lug removed from AC source,
connect an electrical jum er across the two AC lug rongs.
Place the AC switch in the on ositioin, connect one lead of
ohm-meter to the AC lug rongs tied together and touch other
ohm-meter lead in turn to each ex osed metallic arts such as
antenna terminals, hone jacks, etc.
If the ex osed metallic art has a return ath to the chassis, the
measured resistance should be between 1MΩ and 5.2MΩ.
When the ex osed metal has no return ath 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 C rrent Hot Check (See below Figure)
Plug the AC cord directly into the AC outlet.
Do not se a line Isolation Transformer d ring this check.
Connect 1.5K/10watt resistor in arallel with a 0.15uF ca acitor
between a known good earth ground (Water Pi e, Conduit, etc.)
and the ex osed metallic arts.
Measure the AC voltage across the resistor using AC
voltmeter with 1000 ohms/volt or more sensitivity.
Reverse lug the AC cord into the AC outlet and re eat AC
voltage measurements for each es osed metallic art. Any
voltage measured must not exceed 0.75 volt RMS which is
corres onds to 0.5mA.
In case any measurement is out of the limits se cified, there is
ossibility of shock hazard and the set must be checked and
re aired before it is returned to the customer.
Leakage C rrent Hot Check circ it
The source of X-RAY RADIATION in this TV receiver is the
High Voltage Section and the Picture Tube.
For continued X-RAY RADIATION rotection, the
re lacement tube must be the same ty e tube as s ecified in
the Re lacement 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 su lements and addenda, read and follow the
SAFETY PRECAUTIONS on age 3 of this ublication.
NOTE: If unforeseen circumstances create conflict between the
following servicing recautions and any of the safety
recautions on age 3 of this ublication, always follow the
safety recautions. Remember: Safety First.
General Servicing Preca tions
1. Always un lug the receiver AC ower cord from the AC
ower source before;
a. Removing or reinstalling any com onent, circuit board
module or any other receiver assembly.
b. Disconnecting or reconnecting any receiver electrical lug
or other electrical connection.
c.
Connecting a test substitute in arallel with an electrolytic
ca acitor in the receiver.
CAUTION: A wrong art substitution or incorrect
olarity installation of electrolytic ca acitors may result
in an ex losion hazard.
d. Discharging the icture tube anode.
2. Test high voltage only by measuring it with an a ro riate
high voltage meter or other voltage measuring device (DVM,
FETVOM, etc) equi ed with a suitable high voltage robe.
Do not test high voltage by "drawing an arc".
3. Discharge the icture tube anode only by (a) first connecting
one end of an insulated cli lead to the degaussing or kine
aquadag grounding system shield at the oint where the
icture tube socket ground lead is connected, and then (b)
touch the other end of the insulated cli lead to the icture
tube anode button, using an insulating handle to avoid
ersonal contact with high voltage.
4. Do not s ray chemicals on or near this receiver or any of its
assemblies.
5. Unless s ecified otherwise in this service manual, clean
electrical contacts only by a lying the following mixture to
the contacts with a i e cleaner, cotton-ti ed stick or
com arable nonabrasive a licator; 10% (by volume)
Acetone and 90% (by volume) iso ro yl alcohol (90%-99%
strength)
CAUTION: This is a flammable mixture.
Unless s ecified otherwise in this service manual, lubrication
of contacts in not required.
6. Do not defeat any lug/socket B+ voltage interlocks with
which receivers covered by this service manual might be
equi ed.
7. Do not a ly AC ower 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
ositive 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 stra to
any heatsink in this receiver.
Electrostatically Sensitive (ES) Devices
Some semiconductor (solid state) devices can be damaged
easily by static electricity. Such com onents commonly are
called Electrostatically Sensitive (ES) Devices. Exam les of
ty ical ES devices are integrated circuits and some fieldeffect
transistors and semicounductor "chi " com onents. The
following techniques should be used to hel reduce the
incidence of com onent damage caused by static by static
electricity.
1. Immediately before handling any semiconductor com onent
or semiconductor-equi ed assembly, drain off any
electostatic charge on your body by touching a known earth
ground. Alternatively, obtain and wear a commercially
available discharging wrist stra device, which should be
removed to revent otential shock reasons rior to
a lying ower to the unit under test.
2. After removing an electrical assembly equi ed with ES
devices, lace the assembly on a conductive surface such as
aluminum foil, to revent electrostatic charge buildu or
ex osure of the assembly.
3. Use only a grounded-ti soldering iron to solder or unsolder
ES devices.
4. Use only an anti-static ty e 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- ro elled chemicals. These can generate
electrical charges sufficient to damage ES devices.
6. Do not remove a re alcement ES device from its rotective
ackage until immediately before you are ready to install it.
(Most re lacement ES devices are ackaged with leads
electrically shorted together by conductive foam, aluminum
foil or com arable conductive material).
7. Immediately before removing the rotective material from
the ieads of a re lacement ES device, touch the rotective
material to the chassis or circuit assembly into which the
device will be installed.
CAUTION:Be sure no ower is a lied to the chassis or
circuit, and observe all other safety recautions.
8. Minimize bodily motions when handling un ackaged
re lacement ES devices. (Otherwise harmless motion such
as the bruching together of your clothes fabric or the lifting
of your foot from a car eted floor can generate static
electricity sufficient to damage an ES device.)
General Soldering G idelines
1. Use a grounded-ti , low-wattage soldering iron and
a ro riate ti size and sha e that will maintan ti
tem erature within the range or 500°F to 600°F.
2. Use an a ro riate gauge of RMA resin-core solder
com osed of 60 arts tin/40 arts lead.
3. Kee the soldering iron ti 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- ro elled s ray-on cleaners.
5. Use the following unsoldering technique
a. Allow the soldering iron ti to reach normal tem erature.
(500°F to 600°F)
b. Heat the com onent lead until the solder melts.
c. Quickly draw the melted solder with an anti-static,
suction-ty e solder removal device or with solder braid.
CAUTION: Work quickly to avoid overheating the
circuiboard rinted foil.
6. Use the following soldering technique.
a. Allow the soldering iron ti to reach a normal
tem erature (500°F to 600°F)
b. First, hold the soldering iron ti and solder the strand
against the com onent lead until the solder melts.
SERVICING PRECAUTIONS

1-5
c. Qulckly move the soldering iron ti to the junction of the
com onent lead and the rinted circuit foil, and hold it
there only until the solder flows onto and around both the
com onent lead and the foil.
CAUTION: Work quickly to avoid overheating the circuit
board rinted foil.
d. Closely ins ect the solder area and remove any excess
or s lashed 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 ty e, the following
technique should be used to remove and re lace the IC. When
working with boards using the familiar round hole, use the
standard technique as outlined in ara ra hs 5 and 6 above.
Removal
1. Desolder and straighten each IC lead in one o eration by
gently rying u on the lead with the soldering iron ti as the
solder melts.
2. Draw away the melted solder with an anti-static suction-
ty e solder removal device (or with solder braid) before
removing the IC.
Replacement
1. Carefully insert the re lacement IC in the circuit boare.
2. Carefully bend each IC lead against the circuit foil ad and
solder it.
3. Clean the soldered areas with a small wire-bristle brush.
(It is not necessary to rea ly acrylic coating to the areas).
"Small-Signal" Discrete Transistor
Removal/Replacement
1. Remove the defective transistor by cli ing its leads as
close as ossible to the com onent body.
2. Bend into a "U" sha e the end of each of three leads
remaining on the circuit board.
3. Bend into a "U" sha e the re lacement transistor leads.
4. Connect the re lacement transistor leads to the
corres onding leads extending from the circuit board and
crim the "U" with long nose liers to insure metal to metal
contact then solder each connection.
Power O tp t, Transistor Device
Removal/Replacement
1. Heat and remove all solder from around the transistor leads.
2. Remove the heatsink mounting screw (if so equi ed).
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 cli off excess lead.
6. Re lace heatsink.
Diode Removal/Replacement
1. Remove defective diode by cli ing its leads as close as
ossible to diode body.
2. Bend the two remaining leads er endicula y to the circuit
board.
3. Observing diode olarity, wra each lead of the new diode
around the corres onding lead on the circuit board.
4. Securely crim each connection and solder it.
5. Ins ect (on the circuit board co er side) the solder joints of
the two "original" leads. If they are not shiny, reheat them
and if necessary, a ly additional solder.
F se and Conventional Resistor
Removal/Replacement
1. Cli each fuse or resistor lead at to of the circuit board
hollow stake.
2. Securely crim the leads of re lacement com onent around
notch at stake to .
3. Solder the connections.
CAUTION: Maintain original s acing between the re laced
com onent and adjacent com onents and the circuit board
to revent excessive com onent tem eratures.
Circ it Board Foil Repair
Excessive heat a lied to the co er foil of any rinted circuit
board will weaken the adhesive that bonds the foil to the circuit
board causing the foil to se arate from or "lift-off" the board.
The following guidelines and rocedures should be followed
whenever this condition is encountered.
At IC Connections
To re air a defective co er attern at IC connections use the
following rocedure to install a jum er wire on the co er
attern side of the circuit board. (Use this technique only on IC
connections).
1. Carefully remove the damaged co er attern with a shar
knife. (Remove only as much co er as absolutely
necessary).
2. carefully scratch away the solder resist and acrylic coating
(if used) from the end of the remaining co er attern.
3. Bend a small "U" in one end of a small gauge jum er wire and
carefully crim it around the IC in. Solder the IC connection.
4. Route the jum er wire along the ath of the out-away
co er attern and let it overla the reviously scra ed end
of the good co er attern. Solder the overla ed area and
cli off any excess jum er wire.
At Other Connections
Use the following technique to re air the defective co er
attern at connections other than IC Pins. This technique
involoves the installation of a jum er wire on the com onent
side of the circuit board.
1. Remove the defective co er attern with a shar knife.
Remove at least 1/4 inch of co er, to ensure that a
hazardous condition will not exist if the jum er wire o ens.
2. Trace along the co er attern from both sides of the
attern break and locate the nearest com onent that is
directly connected to the affected co er attern.
3. Connect insulated 20-gauge jum er wire from the lead of
the nearest com onent on one side of the attern break to
the lead of the nearest com onent on the other side.
Carefully crim and solder the connections.
CAUTION: Be sure the insulated jum er wire is dressed so
the it does not touch com onents or shar 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.
6.
D
/
E
(PROGRAMME UP/DOWN)
switches the set on from standby.
selects a programme or a menu item.
7.
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.
OK
PR
VOL
PR
VOL
PLAY
P/STILL STOP REC/ITR
REW/ FF/
SLEEP
AUTO
CLOCK/COUNT
TRK
SYSTEM Q.VIEW
SP/LP
?
TEXT
i
0
MUTE TV/AV
MENU
CLEAR/RESETTIMER PROG
123
456
789
EJECT
1
3
4
5
6
7
8
12
13
15
16
10
2
9
11
14
(With TELETEXT)
17
18
19
21
23
22
24
20

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.
OK
PR
VOL
PR
VOL
PLAY
P/STILL STOP REC/ITR
REW/ FF/
SLEEP
AUTO
CLOCK/COUNT
TRK
SYSTEM Q.VIEW
SP/LP
0
MUTE TV/AV
MENU
CLEAR/RESETTIMER PROG
123
456
789
EJECT
1
3
4
5
6
7
8
12
13
10
2
9
11
14
15
(Without TELETEXT)
17
18
19
21
23
22
24
20

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/STILLSTOP/EJECT OKMENU
STAND-BY TAPE-IN TIMER REC
AV2
PR
PR
VOL VOL
VIDEO- IN -AUDIO
ON/OFF
REC/ITR REW/ PLAY FF/ P/STILLSTOP/EJECT OKMENU
STAND-BY TAPE-IN TIMER REC
AV2
PR
PR
VOL VOL
VIDEO- IN -AUDIO
ON/OFF
REC/iTR REW/ PLAY FF/ P/STILL STOP/EJECT MENU OK
VOL
PR
STAND-BY TAPE-IN TMER REC
ON/OFF
AV2
VIDEO- IN -AUDIO
14
13 15 16 17 19 20
20
20
4
18
13 5 6 7 8 910 11 12
2 4
AV2
ON/OFF VOL
PR
REC /ITR REW/ PLAY FF/ P/STILL STOP/EJECT MENU OK
VIDEO- IN -AUDIO
STAND-BY TAPE-IN TIMER REC
;;
;;;;
;;;;;;;
;;;;;;;;
;;;;;;;;;;;
;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;
;;;;;;;;;;;;
;;;;;;;;;
;;;;;;;;
;;;;;
;;;
20
14
13 15 16 17 1918
13 5 6 7 8 910 11 12
2 4
ON/OFF
/
VOL PR STOP/EJECT REW/ PLAY FF/ REC/ITR
AV2
AUDIO
VIDEO
H/P
REC TIMER-REC STAND-BY
IN
13 15 16 10 43
111 12 17 6 5 14 920
2
ON/OFF VOL PR
STOP/EJECT REW/ PLAY FF/ REC/ITR
REC TIMER-REC STAND-BY
13 15 16 103
111 12 17 6 5 14 920
4
20
2
14
13 15 16 17 1918
13 5 6 7 8 910 11 12
2 4
14
13 15 16 17 1918
13 5 6 7 8 910 11 12
2 4
P
L
A
Y
R
E
W
/
F
F
/
ON/OFF
VOL PR
STOP/EJECT
REC/ITR
RECTIMERRECSTAND-BY
P
L
A
Y
R
E
W
/
F
F
/
ON/OFF
VOL PR
STOP/EJECT
REC/ITR
RECTIMERRECSTAND-BY
13
1217 15 616 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
se arate the back cover from the front cabinet and P/cord
holder barcket.(Refer to Fig. 2-1, 2-2)
2. Main 2 PCB Removal
Gras both sides of the su ort frame and ull it back and u .
3. Main Chassis Removal
1) Remove 2 screws securing the Main chassis to the front
cabinet.
2) Gras both sides of the chassis and ull it back
4. Speaker Assembly Removal
1) Remove the connector between the s eaker and the main
chassis.
2) To remove the s eaker, remove the screw.
5. CPT REMOVAL
1) After removal of VCR chassis and s eaker 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 se arate CPT from front cabinet.
PICTURE TUBE HANDLING CAUTION
Due to high vacuum and large surface area of icture tube, great
care is needed when handling the icture tube. Always lift the
icture tube by gras ing it firmly around face late. NEVER LIFT
THE TUBE BY ITS NECK. The icture tube must not be scrated
or subject to excessive ressure as gracture of the glass may
result in an im losion of considerable violence which can cause
ersonal injury or ro erty 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
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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
4
POLE
ROTATION DIRECTION
OF BOTH TABS
OPPOSITE
SAME
OPPOSITE
SAME
MOVEMENT OF RED
AND BLUE BEAMS
BB
RR
OR
OR
BR BR
OR
B
R
B
R
BROR BR
6
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
GREEN
BLUE RED
GREEN
GREEN
ADJUSTMENT
VIEWING
AREA
UP/DOWN ROCKING OF THE YOKE
CAUSES OPPOSITE ROTATION OF RED
AND BLUE RASTERS
ADJUSTMENT
VIEWING
AREA
RED
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 PAL-
B/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
P2 P3
FE HEAD
P1
TENTION ARM
P4
P0
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
P2 P3
FE HEAD
P1
TENTION ARM
P4
P0
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
P2 P3
FE HEAD
P1
TENTION ARM
P4
P0
P2
<A> P2 POST ADJUSTMENT
P3
<B> P3 POST ADJUSTMENT
D
<C> FINAL ADJUSTMENT WAVWFORM
P2P2
<A> P2 POST ADJUSTMENT
P3
P3
<B> P3 POST ADJUSTMENT
FIGURE 2> P2/P3 ADJUSTMENT WAVEFORM
D
<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 level-
meter 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,X-
DISTANT(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.
1
2
CTL WAVEFORM
1
2
CTL WAVEFORM
1
2
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
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 5ᒠinside 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
V
140V
BLACK LEVEL(DC)
GND
V
No
1
2
140V ±3V
130V ±3V
Adjust Voltage Remark Note
Model(14/20/21)
EU
NON-EU
9000K
10000K
288
281
295
288
X Y Color Temperature
Model(15 FLAT )
EU
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
25
31
32
32
15
25
31
32
32
15
25
31
32
32
15
Adjust Cintents YYYY
3-7