Adjustment Instructions - LG 21FU3RL Service Manual

1. Application Object
These adjustment instructions are applicable to CW81A/B
Chassis.
2. Notes
(1) Because this is a cold chassis, it is not necessary to use
an isolation transformer. However,operating it using a
transformer between the power supply line and chassis
input to prevent electric shock and to protect the test
instrument.
(2)All adjustments must be done in correct sequence.
However, for better productivity, it can be changed in a pre-
permitted range.
(3) Environment conditions: If not specified, it must be done in
following conditions.
1) Temperature: 25±5°C
2) Humidity : 65±10%
(4) AC Voltage : 100-240V ±10%, 50/60Hz
(5) If not specified, the receiver must be operated for more
than 20 minutes prior to the adjustment.
(6) Signal: Received the standard color signal. (65dB±1dBuV)
PAL/SECAM : LG standard signal means the digital pattern
PAL_EU 05CH
(7) If not specified, APC ON is APC CLEAR(DYNAMIC).
3. AGC Voltage Adjustment
3-1. Necessary Instrument
: Digital Multi meter : 1 set
- Max Input Current : Over 1A/ Max Input Voltage : 500Vdc
- Measurement Range : 10mV-100mVdc/ Accuracy : 0.03%
3-2. Adjustment Preparation
1) Input in the 75Ω cable 65dB(±1dB) LG standard signal.
2) Connect the multi-meter to J105(AGC Check Marking)
3-3. Adjustment
(1) Press the "INSTART" key of factory remote control and
select "VP0 (RF AGC)" adjustment mode.
F
(2) Press the VOL +/-( /
reading as shown below.
(3) CAUTION : Since the signal strength can be easily
changed by the condition of signal cable , you
need to check the signal strength frequently in
order to prevent misadjustment.
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes

ADJUSTMENT INSTRUCTIONS

G
)Key until the multi-meter shows
4. Screen Voltage Adjustment
4-1. Adjustment (Use factory remote control)
(1) Input in the 75Ω cable LG standard signal (Digital
Pattern,480NC)
(2) Press the "ADJ" key of factory remote control once to make
the TV set display horizontal line.
(3) Turn the screen volume on the FBT clockwise until the
horizontal line is visible and turn it counterclockwise until
horizontal line faintly visible.
(Exit screen voltage adjustment by press "Enter(
factory remote control.)
5. Purity and Convergence Adjustment
5-1. Purity Adjustment
(1) Adjustment Preparation
1) Receive Red Raster Pattern for purity adjustment.(51ch)
2) Demagnetize the CPT and Cabinet with a degaussing
coil.
(2) Adjustment
1) Pre-adjust the static convergence (STC) with the 4 and
6pole magnet.
2) If the horizontal Line is inline with CPT Mark,2-Pole
magnet should direct 3-9 o'clock direction
3) If not,direct 2-Pole magnet handle toward 6-12 o'clock
direction and adjust the Horizontal Line to fall onto the
mark opening the magnet at an angle.
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4) Push the DY(deflection yoke) all the way to the CPT
funnel.
5) Turn the purity magnet(2-pole magnet) so that the
"green" color portion of left side and the "blue" color
portion on the right side have equal amount of
color.
G R
6) Pull the DY slowly backward and fix it when the whole
screen becomes red. (The specified torque for fixing DY
screw should be 10Kg/cm.)
G R
5-2. Convergency Adjustment
(1) Necessary Instrument
1) Degaussing Coil
2) Convergency fixing instrument (special tools)
(2) Adjustment Preparation
1) Operate the unit at the least 15 minutes before
adjustment.
2) Using degaussing coil,remove the stains on CPT &
Cabinet.
3) Received the Cross Hatch Pattern for Convergence
(09ch).
4) Let the Contrast in normal luminance level.
- 5 -
G R B
B
<Fig. 1>
R
B
<Fig. 2>
LGE Internal Use Only
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