Adjustment - LG 21FJ4AB/RB Service Manual

1. Scope of Application
These instructions are applied to MC-059B 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) Adjustment must be done in the correct order.
3) The adjustment must be performed in the circumstance of
25 ± 5°C of temperature and 65 ± 10% of relative humidity
if there is no specific designation.
4) The input voltage of the receiver must keep (100-240~ ±
10%, 50/60Hz) in adjusting
5) The receiver must be operated for about 15 minutes prior to
the adjustment. But adjusting on the board can be done in
jig state right away.
6) Signal: The standard color signal is approved in 65±1dBuV.
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 LG standard signal into 75Ω antenna terminal (or
PAL-B/G 05CH)
2) Connect the digital multi-meter to terminal(with Hole/
J105) with AGC Check.

3-3. Adjustment

1) Select the VP 0(RF AGC) adjustment mode by pressing
IN-START key on the SVC remote control.
2) After select the RF AGC using CH +/- key, adjust the
multi-meter voltage to be as shown below.
- 6700MF0014A(LG INNOTEK): 2.3±0.05V, 65dBu,
- 6700PF0006B(SANYO): 2.3±0.05V, 65dBu,
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 error.
4. Screen Voltage Adjustment
4-1. Adjustment of Screen Manually
(Using SVC Remote Control)
1) Receive the PAL(SECAM) signal into RF mode
regardless of channel.
2) If you press the "ADJ' key on LINE SVC remote control,
changes to screen adjustment mode.
3) Adjust the Screen Vol. of FBT to appear Horizontal Line
and adjust the Screen Vol. of FBT at disappear point
Horizontal Line.(Press the Enter(
mode)
ADJUSTMENT
TAEW-G013D
115-B-A86EL
) key to exit SVC
A
5. Purity and Convergence Adjustment
5-1. Purity Adjustment
(1) Adjustment Preparation
1) Receive Red Raster Pattern for purity adjustment.
2) Demagnetize the CPT and Cabinet with a degaussing
coil.
(2) Horizontal Line Adjustment
1) Pre-adjust the static convergence (STC) with the 4 and
6pole magnet.
2) Check if the beam land at mask hole by setting two 2-
pole magnets in opposite direction respectively.
3) If not, adjust 2-pole magnet so the beam as to land at
mask hole accurately.
(3) Purity Adjustment
1) Adhere DY closely to CPT.
2) Receive Red Pattern and adjust the 2-Pole magnet so
Red color Bar as to locate center and make the portion
of Green color and Blue color same.<Fig.1>
G R
3) Make the full screen Red by pulling DY back slowly.
(When adhering DY, use the electric driver of which
turning force is lower than 10Kg/Cm) <Fig. 2>
G R
5-2. Convergency Adjustment
(1) Necessary Instrument
1) Degaussing Coil
2) Convergency fixing instrument
(2) Preliminary steps
1) Heat run over 30 minutes before adjustment.
2) Demagnetize the CPT and Cabinet by using degaussing
coil.
3) Receive Cross Hatch Pattern.(EU09CH)
4) Adjust Contrast and Brightness for easy observation.
(3) Static Convergence (STC) Adjustment
1) Receive Cross Hatch Pattern(EU09CH)
2) Adjust the focus first seeing to it that the WHITE color
picture quality is sharp enough.
3) Open two 4-Pole magnets until vertical Red and Blue
lines are unified.
4) Rotate the 4-Pole magnets keeping the angle between
two 4-Pole magnets until horizontal Red and Blue lines
are unified.
5) Open two 6-Pole magnets until vertical Red and Green
lines are unified.
6) Rotate the 6-Pole magnets keeping the angle between
two 4-Pole magnets until horizontal Red and Blue lines
are unified.
- 8 -
G R B
B
<Fig. 1>
R
B
<Fig. 2>