Service Adjustment - Sharp 20PL84 Service Manual

Table of Contents

Advertisement

Ë SERVICE ADJUSTMENT
RF AGC Adjustment
1. Receive a good local channel.
2. Enter the service mode signal category and select
the service adjustment "AGC".
3. Set the data value to point where no noise or beat
appears.
4. Select another channel to confirm that no noise or
beat appears.
No. Adjusting point
2
1
SUB-TINT (I
C
1. Receive the "Colour Bar" signal through AV in.
BUS CON-
2. Connect the oscilloscope to TP853 (Pin (5) of
TROL)
3. Call the "SUB-TINT" mode in service mode. Ad-
4. "SUB-TINT" bus data decrease 4 steps to get fi-
5. Clear the SERVICE mode.
HORIZONTAL AND VERTICAL DEFLECTION LOOP ADJUSTMENT
No. Adjusting point
1
V-SLOPE(I
2
C
1. Receive Monoscope Pattern Signal.
BUS CON-
2. Call the "V-LIN" mode.
TROL)
3. Increase or decrease "V-LIN" by Volume key till
2
2
V-CENTER (I
C
1. Call the "V-CENT" mode.
BUS CON-
2. Increase or decrease "V-CENT" by Volume key till
TROL)
3
V - AMP (I
2
C
1. Call the "V-AMP" mode.
BUS CON-
2. Increase or decrease "V - AMP" by Volume key to
TROL)
4
S-CORREC-
TION (I
2
C BUS
FIXED DATA, NO NEED TO ADJUST.
CONTROL)
H - CENTER
5
1. Call the "H-CENT" mode.
2. Increase or decrease "H-CENT" by Volume key
6
Focus
1. Receive the "Monoscope Pattern" signal.
adjustment
2. Press R/C to set Picture NORMAL condition.
3. Adjust the focus control to get the best focus.
CHROMA ADJUSTMENT
Adjusting procedure/conditions
P882) BLUE-OUT.
» Range
: 100mV/div. (AC)(Use Probe 10:1)
» Sweep time : 10 µsec/div.
just the "SUB-TINT" bus data to obtain the wave-
form shown as Fig 1.
nal waveform. (Fig 2.)
Adjusting procedure/conditions
the horizontal line in the center of monoscope is
just at the position where the blanking starts.
the picture is centered.
set overscan of 10.0% typical.
Adjustment Spec 10.0% range ±1%.
to center the picture horizontal.
11
Waveform and others
FINAL WAVEFORM
WAVEFORM 1
SAME LEVEL
W
Y CY G MG R B
Fig 1
Fig 2
Waveform and others
20PL84

Advertisement

Table of Contents
loading

Table of Contents