File name lg_chassis-mc-8cb.pdf
Y Safety Precautions : Screen Voltage Adjustment
1. It is safe to adjust after using insulating transformer
between the power supply line and chassis input to Test Point : RK (Red Cathode of CPT Board)
prevent the risk of electric shock and protect the Adjust : Screen Control of FBT
2. Never disconnect leads while the TV receiver is on.
3. Don't short any portion of circuits while power is on. 1) Tune the TV set to receive a color bar pattern.
4. The adjustment must be done by the correct appliances. 2) Press PSM (RED) button on remote controller. (standard
But this is changeable in view of productivity. picture)
5. Unless otherwise noted, set the line voltage to 3) Connect the probe of oscilloscope to the RK (Red
230Vac!10%, 50Hz. Cathode) of CPT Board.
4) Adjust Screen Volume of FBT so that the waveform is the
Y Test Equipment required same as below figure.
1. RF signal generator (with pattern generator)
2. DC Power Supply
3. Multimeter (volt meter) Horizontal
4. Oscilloscope Black level
5. Color analyzer
150 3V for 25" LG CPT
150 3V for 29" LG CPT
: RF AGC (Automatic Gain Control) Adjustment GND for dc
Test Point : AGC TP (J2) The waveform of RK(Red Cathode) of CPT Board
Adjust : Remote Control
The RF AGC was aligned at the time of manufacture for
optimum performance over a wide range conditions. : Focus Adjustment
Readjustment of RF AGC should not be necessary unless
unusual local conditions exist, such as ; NOTE: This adjustment should be performed after warming
up for 10 minutes.
1) Channel interference in a CATV system.
2) Picture bending and/or color beats, which are unusually Test Point : Ob