068aadj.pdf part of LG 068aadj 068aadj.pdf, LG TV cf-20f69 068aadj.pdf text manual preview

Text preview for : 068aadj.pdf part of LG 068aadj LG TV cf-20f69 068aadj.pdf

Back to : 068aadj.pdf | Home

ADJUSTMENT
Y Safety Precautions
1. It is safe to adjust after using insulating transformer
between the power supply line and chassis input to TUNER 6700VPV002A(LG C&D) 6700VPV002B(LG C&D)
prevent the risk of electric shock and protect the
AGC Voltage 2.5 ! 0.1V 3.0 ! 0.1V
instrument.
2. Never disconnect leads while the TV receiver is on. Default AGC Data 24 24
3. Don't short any portion of circuits while power is on.
4. The adjustment must be done by the correct appliances.
But this is changeable in view of productivity.
5. Unless otherwise noted, set the line voltage to 230Vac!10%, : Screen Voltage Adjustment
50Hz.
Test Point : RK (Red Cathode of CPT Board)
Y Test Equipment required Adjust : Screen Control of FBT
1. RF signal generator (with pattern generator)
2. DC Power Supply
3. Multimeter (volt meter) 1) Input the Color Bar Pattern into Antenna jack.
4. Oscilloscope 2) Select CutOff of SVC-3 mode.
5. Color analyzer 3) Turn the screen control clockwise until the Horizontal line
is visible and turn it counterclockwise until the Horizontal
line is faintly visible.

: RF AGC (Automatic Gain Control) Adjustment

Test Point : AGC TP (J17) : Focus Adjustment
Adjust : Remote Control
NOTE: This adjustment should be performed after warming
up for 10 minutes.
The RF AGC was aligned at the time of manufacture for
optimum performance over a wide range conditions. Test Point : Observing Display
Readjustment of RF AGC should not be necessary unless Adjust : Focus control of FBT
unusual local conditions exist, such as ;

1) Channel interference in a CATV system. 1) Input the Color Bar Pattern into Antenna jack.
2) Picture bending and/or color beats, which are unusually 2) Adjust the Focus control of FBT for best overall focus.
due to excessive RF signal input when the receiver is too
close to a transmitting tower or when the receiver is
connected to an antenna distribution system where the RF
signal has been amplified. In this case, the input signal : VCO Adjustment
should be attenuated (with pad or filter) to a satisfactory
level. 1) Input Digital Pattern into Antenna jack.
3) Picture noise caused by "broadcast noise" or weak signal. 2) Select A-PIF of SVC-4 mode.
If the broadcast is "clean" and the RF signal is at least 3) Press VOLF/G button and A-PIF will be changed 0 to 1
1mV (60dBu), the picture will be noise free in any area. while the number of PIF-C is rolling.
4) When PIF-C stops rolling, A-PIF will be changed 1 to 0 and
Adjusting RF AGC to one end of rotation will usually cause a VCO adjustment is finished.
relatively poor signal to noise ratio;
Caution : Do not press the Volume button again in A-PIF mode
Adjusting to the other end of rotation will usually cause a
after adjustment is finished.
degradation of over load capabilities resulting in color beats or
adjacent channel interference.
1. To get into SVC mode
1) Press OK buttons on both TV set and Remote Control at
Adjustment the same time.
2) Press Yellow button to select OPTION-1, OPTION-2,
1. Connect RF signal (65dB!0.5dB) and turn on the TV.
OPTION-3 or OPTION-4.
2. Press OK buttons on TV set and Remote Controller at the
3) Press PR E/D button to select an adjustment.
same time to get into SVC mode.
4) Press VOL F/G button to change the data.
3. Press Channel UP/DOWN button on the Remote Controller
several times to find AGC. 2. To memorize the adjusted data into EEPROM
4. Press Volume UP/DOWN button until the AGC Voltage is Press OK button.
the same as the Table below.
3. To get out from SVC mode
5. Press OK(Y) button to memorize the data.
Press TV/AV or Power button.

- 1 -
: Deflection Data Adjustment (Line SVC-2) : White Balance Adjustment.(LINE SVC-1)

1. Preparation for Adjustment NOTE : This adjustment should be performed after screen voltage
1) Select SVC-2 Mode. adjustment.
2) Tune the TV set to receive Digital Pattern and set ARC
Mode to Standard. 1) Tune the TV set to receive 100% white pattern.
2) Select SVC-1 Mode.
3) Press PR UP/DOWN key to select BG, GG, BG, GC.
2. Initial deflection data and average data for CPT Adjust BG, GG on Brightness 40!1FL and BG, GC on
Brightness 4.5!0.5FL with VOLF/G key to get the color value.
Status Default 21" LG 20" LG 14" LG 4) Adjust BG, GG from the initialized data to get the color value of
X=281!8, Y=288!8.
VL 9 9 9 9 5) R,G,B initial data and average data

VS 3 3 1 3
Status Initial Data Remark
VA 37 34 39 37
RC 127
HS 11 12 10 11
GC 147
SC 2 2 2 2
BC 123

GG 59
3. Adjustment
1) VL(Vertical Linearity) Adjustment BG 64
Select VL adjustment mode to adjust the upper and lower
vertical size to be the same for horizontal center line.

2) VS(Vertical Shift) Adjustment
Adjust the geometrical horizontal center line of the screen to
be coincided with the vertical center line of CPT. : Sub Brightness Adjustment

3) VA(Vertical Amplitude) Adjustment NOTE: This adjustment should be performed after White
Adjust the upper and lower part of big circle of the received Balance adjustment.
pattern to be placed on 6~7mm from the valid screen.
1) Input FUBK pattern to Antenna jack.
4) HS(Horizontal Shift) Adjustment 2) Select S-BRI of SVC-3 mode.
Adjust the geometrical vertical center line of the received 3) Press VOL F/G until (a) and (b) of FUBK are distinct and
screen to be coincided with the horizontal center line of CPT. press VOL G twice more.

(a) (b)

5) SC(Vertical S Correction) Adjustment
Adjust the width of upper/center/lower grid of the received
pattern to be the same.

: SECAM Background Color Adjustment(CT-, CF-)
: OPTION Adjustment (SVC MODE:OPTION-1,
1. Preparation for Adjustment OPTION-2)
Select