Matsui 20OT Schematic
1MATSUI 20 OT
General Information
Also Covers
20 OR & 200 T & 200 R
Electrical
Adjustments
1. BEFORE MAKING ELECTRICAL
ADJUSTMENTS
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 (YG6260M).
Remove all old silicon before applying new
silicon.
1-1: Prepare the following measurement
tools for electrical adjustments.
1. Sweepmarker Generator
2. Oscilloscope
3. Digital Voltmeter
4. Color Bar Generator
2. BASIC ADJUSTMENTS
2-1: AFT
1. Connect the AFT adjustment oscillator
(39.5MHz) to TP of the tuner pack.
2. Connect the digital voltmeter to TP201.
3. Adjust L202 until the digital voltage is 3.5V ±
0.1V.
2-2: BRIGHT, AGC, CONTRAST AND COLOR
On-Screen Display Adjustment
Connect the GND through the 6.8k ohm resistor
to the point (A) as shown in MAJOR COMPONENTS LOCATION GUIDE.
The adjustment mode display will appear as
shown in Fig. 2-1.
2-2-A: BRIGHT
1. Receive the monochrome pattern.
2. Activate the adjustment mode display and
press the 6 key.
3. Press the VOL. UP/DOWN key on the remote
control until 0% of gray scale begins to
lighten.
2-2-B: AGC
NOTE
Adjust after performing adjustments in section 2-1.
In case of weak electric field.
1. Tune to a noisy channel.
2. Activate the adjustment mode display and
press the 3 key.
3. Press the VOL. UP/DOWN key on the remote
control until noise is at minimum.
4. Change the channel, confirm that the other
channels are normal.
In case of strong electric field.
(Radio frequency interference can cause
diagonal streaks to appear.)
1. Activate the adjustment mode display and
press the 3 key.
2. Press the VOL. UP/DOWN key on the remote
control until diagonal streaks are at minimum.
3. If there is still a problem after pressing the
VOL. UP/DOWN key on the remote control,
install an attenuator to the antenna terminals,
then repeat step 1.
4. Confirm that noise does not appear.
5. Change the channel, confirm that the other
channels are normal.
2-2-C: CONTRAST
1. Activate the adjustment mode display and
press the 5 key.
2. Adjust the VOL. UP/DOWN key on the
remote control until the bar step is set to fhe
“32 “(20”) or “0”(14).
2-2-D: COLOR (PAL)
1. Receive the color bar pattern.
2. Connect the oscilloscope to TP801.
3. Activate the adjustment mode display and
press the 4 key.
4. Adjust the VOLTS RANGE VARIABLE knob
of the oscilloscope until the range between
white 100% and 0% is set to 4 scales on the
screen of the oscilloscope.
5. Press the VOL. UP/DOWN key on the remote
control until the red color level is adjusted to
75% of the white level. (Refer to Fig. 2-2)
2-3: CUT OFF
1. Receive the color bar pattern.
2. Set the AFT switch ON position.
3. Connect the oscilloscope to TP802
4. Adjust VR803 until voltage is 150VDC (20”)
140VDC (14”) (Refer to Fig. 2-3)
2-4: FOCUS
1. Receive the broadcasting signal.
2. Adjust the focus control until picture is
distinct.
2-5: VERTICAL SIZE
1. Receive the crosshatch pattern from the color
bar generator.
2. Adjust the bright and contrast controls until
the crosshatch pattern is distinct.
3. Adjust VR401 until the center of crosshatch is
square.
4. Receive broadcasting signal, then confirm
picture is normal.
2-6: VERTICAL POSITION
1. Receive the color bar pattern.
2. Using the remote control, set brightness and
contrast to maximum position.
3. Adjust the value of R424 and R425 until
horizontal line of the color bar comes to
approximate center of the CRT.
NOTE
R424 and R425 are fixed components. Use a
variable resistor or capacitor to determine the
optimal value and insert that value component.
Lessen the value of R424. Picture will move
4mm up. Lessen the value of R425. Picture will
move 4mm down.
2-7: HORIZONTAL POSITION
1. Receive the color bar pattern.
2. Using the remote control, set brightness and
contrast to maximum position.
3. Adjust VR403 until the color width of both
screen edges are equal.
4. Receive the broadcasting signal, then confirm
picture is normal.
Component
Location
Guide
CRT (200R) Diagram
NOTE
Use the 1 - 7 keys on the remote control to
select the options shown in Fig. 2-1.
Press the 7 key to end the adjustments.
ADJUSTMENT MODE
1. AGC/BRI/COL AUTO
2. SUB BRIGHT AUTO
3. AGC MANUAL
4. COLOR MANUAL
5. CONTRAST MANUAL
6. BRIGHT MANUAL
7. END
Fig.2-1
Electrical Adjustments / Component Location / CRT Diagram (20 OR) / Microcontroller Diagrams (20 OR) (20 T) / Video Audio Diagrams (20 OR) (20 T)
Fig. 2-2
Fig. 2-3
Power & Deflection Diagram / Text Diagram / Tuner CRT Diagram (20 OT) / Waveforms
2MATSUI 20 OT
Microcontroller (20 OT) Diagram Microcontroller (20 OR) Diagram
Electrical Adjustments / Component Location / CRT Diagram (20 OR) / Microcontroller Diagrams (20 OR) (20 T) / Video Audio Diagrams (20 OR) (20 T)
Power & Deflection Diagram / Text Diagram / Tuner CRT Diagram (20 OT) / Waveforms
3MATSUI 20 OT
Video Audio (20 OT) Diagram
Electrical Adjustments / Component Location / CRT Diagram (20 OR) / Microcontroller Diagrams (20 OR) (20 T) / Video Audio Diagrams (20 OR) (20 T)
Power & Deflection Diagram / Text Diagram / Tuner CRT Diagram (20 OT) / Waveforms
Loading...