LG CT-29Q90IP User manual

COLOR TV
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
CHASSIS : MC-006A
MODEL:CT-29Q90IP
MODEL:CF-29F96IP
website:http://biz.LGservice.com
e-mail:http://www.LGEservice.com/techsup.html

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CONTENTS
Contents ................................................................................................................. 2
Safety Precautions ............................................................................................3
Specifications ..................................................................................................... 4
Control Descriptions ........................................................................................ 5
Disassembly Instructions ............................................................................. 8
Adjustment Instructions ............................................................................... 9
Trouble Shooting .............................................................................................. 19
Wiring Diagram ................................................................................................. 25
Exploded View .................................................................................................. 26
Exploded View Parts List..............................................................................27
Replacement Parts List ............................................................................... 28
SVC. Sheet ................................................................................................................

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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

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SPECIFICATIONS
Note : Specification and others are subject to change without notice for improvement.
¡Video input system:
PAL-B/G, D/K, I/I
SECAM-B/G, D/K/L/L’
NTSC M
NTSC 4.43(AV)
¡Intermediate Frequency (Unit : MHz)
VISION IF : 38.9MHz,33.9MHz(SECAM-L’)
COLOR IF : 34.47MHz(4.43)
35.32MHz(3.58) : NTSC-M
VIF-4.25000MHz
VIF-4.40625MHz
SOUND IF : 33.4MHz (B/G)
32.9MHz (I/I)
32.4MHz (D/K,L)
34.4MHz (M)
40.4MHz (L’)
¡Power requirement : 110~240V, 50/60Hz
¡Power consumption : 165W
¡CPT : Flat CPT
¡Tuning system :
FVS
100 Programme memory
¡
Antenna input impedance : VHF/UHF 75 ohm, unbalanced
¡OSD (On Screen Display) : EZ MENU Type
¡Voice coil impedance : 8 ohm
¡Sound output : R,L Out : 7W+7W
Center : 5W
Woofer : 20W
¡External connection : Head Phone Jack
S-VIDEO in
A/V in :1 pair
VGA input
Scart 1(Full)
A/V in/out
Scart 2(Half)+Audio out
A/V in/out
¡External In/Output
Audio-In:0.5Vrms¡3db,over 10Kohm
Audio-Out:0.5Vrms¡3db,below 1Kohm
Video-In/Out:1Vp-p¡3db,75ohm
R,G,B In:0.7Vp-p¡3db
¡Feature : Auto programme/Manual programme
SVM (Scanning Velocity Modulation)
Digital Eye
Digital Comb Filter
Auto Sleep
Dynamic Focus
Programme Editing
PSM (Picture Status Memory)
SSM (Sound Status Memory)
CTI
Teletext (128 page)
Turbo Search, Picture & Sound
ACMS
ARC (Zoom 1/ZOOM 2, 16:9¡Œ4:3)
2 TUNER PIP(Double Window PIP)
MUP mode(Program Scan)
VGA input
Child Lock :
¡Tuning range
Band
VHF-Low
VHF-High
Hyper
UHF
S1'-S3', S1
S2-S10,
S11-S20
S21-S41
For TV For CATV
B/G
Ch2-4
Ch5-12
D/K
Ch1-5
Ch6-12
I/I
Ch4-13
NTSC
Ch2-13
Ch21-69 Ch14-69
In the Lock On state the TV can only be
operated by the Remote Controller.
If any button on the front panel is pressed,
"Child Lock" is displayed on the screen but
the button's function is not performed.
To cancel of this mode, select lock off with
menu button on remote controller only.
(): SECAM
Front or
Side
Back

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DESCRIPTION OF CONTROLS
All the functions can be controlled with the remote control handset.
Some functions can also be adjusted with the buttons on the front
panel of the set.
Remote control handset
Before you use the remote control handset, please install the bat-
teries. See the next page.
1. POWER
switches the set on from standby or off to standby.
2. DRP (Digital Reality Picture)
switches DRP 1250 or 100.
3. TURBO SOUND BUTTON
selects Turbo sound.
4. PIP BUTTONS
PIP
switches the sub picture on or off.
PR +/ -
selects a programme for the sub picture.
SWAP
alternates between main and sub picture.
INPUT
selects the input mode for the sub picture.
SIZE
adjusts the sub picture size.
STILL
freezes motion of the sub picture.
POSITION
relocates the sub picture in clockwise direction.
2/12 PIP
switches on or off the programme scan mode through 12 sub
pictures .
5. MENU
selects a menu.
6. D / E(Programme Up/Down)
selects a programme or a menu item.
switches the set on from standby.
F / G (Volume Up/Down)
adjusts the volume.
adjusts menu settings.
OK
accepts your selection or displays the current mode.
7. NUMBER BUTTONS
switches the set on from standby or directly select a number.
8. PSM (Picture Status Memory)
recalls your preferred picture setting.
9. I/II
selects the language during dual language broadcast.
selects the sound output (option).
10. VCR BUTTONS
control a LG video cassette recorder.
123
456
7
PSM SSM
8
0
POSITION STILL
2/12PIP
MIX
REVEAL
?
M
TIME
SIZE
LIST
SLEEP
I/II EYE
ARC
STOP REC
P/STILL
REW FF
PLAY
9
POWER
DRP TV/AV
SOUND PICTURE
TURBO
PIP TEXT
PR - PR +
INPUTSWAP
MENU PR
VOL OK VOL
PR
MUTE
1
2
3
4
5
6
7
8
10
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