ELECTRICAL ADJUSTMENTS
1.
Read and perform these adjustments when repairing the
circuits or replacing electrical parts or PCB assemblies.
CAUTION
•
•
•
•
Use an isolation transformer when performing any
service on this chassis.
Before removing the anode cap, discharge electricity
because it contains high voltage.
When removing a PCB or related component, after
unfastening or changing a wire, be sure to put the wire
back in its original position.
Inferior silicon grease can damage IC's and transistors.
When replacing IC's and transistors, use only specified
silicon grease.
Remove all old silicon before applying new silicon.
1. Oscilloscope
2. Digital Voltmeter
On-Screen Display Adjustment
In the condition of NO indication on the screen.
Press the VOL. DOWN button on the set and the
Channel button (9) on the remote control for more than
1 second to appear the adjustment mode on the screen
as shown in Fig. 1-1.
1.
Fig. 1-1
Use the Channel UP/DOWN button or Channel button
(0-9) on the remote control to select the options shown
in Fig. 1-2.
Press the MENU button on the remote control to end
the adjustments.
2.
3.
Prepare the following measurement tools for electrical
adjustments.
FUNCTION
OSD H
CUT OFF
RF. AGC
---
H. POSI
V. POSI
H. SIZE
V. SIZE
V. CENT
V. LIN
VS. CORR
G. DRV
B. DRV
R. BIAS
G. BIAS
B. BIAS
BRI
NO.
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
FUNCTION
SUBCONT
UNI COL
---
TINT
SHARP
RGB CONT
PARABOLA
TRAPEZIU
COR TOP
COR BTM
V EHT
H EHT
FM. LVL
LEVEL
SEP1
SEP2
T. STE
NO.
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
2. BASIC ADJUSTMENTS
TV
00 OSD 15
BEFORE MAKING ELECTRICAL
ADJUSTMENTS
Fig. 1-2
2-1: CONSTANT VOLTAGE
1.
2.
3.
Set condition is AV MODE without signal.
Connect the digital voltmeter to TP002.
Adjust the VR502 until the digital voltmeter is 115
±
1V.
2-2: RF AGC
1.
2.
3.
4.
Receive a 70dB monoscope pattern.
Connect the digital voltmeter between the TP001 and
the GND.
Activate the adjustment mode display of Fig. 1-1 and
press the channel button (02) on the remote control to
select "RF. AGC".
Press the VOL. UP/DOWN button on the remote
control until the digital voltmeter is 1.95
±
0.05V.
2-3: CUT OFF
1.
2.
3.
4.
Adjust the unit to the following settings.
G. DRIVE=64, B. DRIVE=64, R. BIAS=32, G. BIAS=32,
B. BIAS=32, BRIGHTNESS=64, UNI COLOR=50.
Place the set with Aging Test for more than 15 minutes.
Activate the adjustment mode display of Fig. 1-1 and
press the channel button (01) on the remote control to
select "CUT OFF".
Adjust the Screen Volume until a dim raster is obtained.
2-4: WHITE BALANCE
NOTE: Adjust after performing CUT OFF adjustment.
1.
2.
3.
4.
5.
6.
7.
8.
Place the set with Aging Test for more than 10 minutes.
Receive the white 100% signal from the Pattern
Generator.
Using the adjustment control, set the brightness and
contrast to normal position.
Activate the adjustment mode display of Fig. 1-1 and
press the channel button (13) on the remote control to
select "R. BIAS".
Using the VOL. UP/DOWN button on the remote control,
adjust the R. BIAS.
Press the CH. UP/DOWN button on the remote control to
select the "G. DRV", "B. DRV", "G. BIAS" or "B. BIAS".
Using the VOL. UP/DOWN button on the remote control,
adjust the G. DRV, B. DRV, G. BIAS or B. BIAS.
Perform the above adjustments 6 and 7 until the white
color is looked like a white.
2-5: FOCUS
1.
2.
3.
Receive a 70dB monoscope pattern.
Turn the Focus Volume fully counterclockwise once.
Adjust the Focus Volume until picture is distinct.
2-6: HORIZONTAL POSITION
1.
2.
3.
4.
Receive the center cross signal from the Pattern
Generator.
Using the remote control, set the brightness and
contrast to normal position.
Activate the adjustment mode display of Fig. 1-1 and
press the channel button (04) on the remote control to
select "H. POSI".
Press the VOL. UP/DOWN button on the remote
control until the right and left screen size of the vertical
line becomes the same.
