Samsung CW28C7VH2X XEO ch S53A, Elektronika, Schematy
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Alignment and Adjustments
4. Alignment and Adjustments
4-1 General Alignment Instructions
1. Usually, a color TV-VCR needs only slight
touch-up adjustment upon installation. Check
the basic characteristics such as height,
horizontal and vertical sync and focus.
5. Avoid overload. Excessive signal from a
sweep generator might overload the front-end
of the TV. When inserting signal markers, do
not allow the marker generator to distort test
results.
2. Observe the picture for good black and white
details. There should be objectionable color
shading; if color shading is present,
demagnetize, perform purity and convergence
adjustments described below.
6. Connect the TV only to an AC power source
with voltage and frequency as specified on the
backcover nameplate.
3. Use the specified test equipment or its
equivalent.
7. Do not attempt to connect or disconnect any
wires while the TV is turned on. Make sure
that the power cord is disconnected before
replacing any parts.
4. Correct impedance matching is essential.
8. To protect against shock hazard, use an
isolation transformer.
4-2 Automatic Degaussing
A degaussing coil is mounted around the
picture tube, so that external degaussing after
moving the TV should be unnecessary. But
the receiver must be properly degaussed upon
installation.
If the chassis or parts of the cabinet become
magnetized, poor color purity will result. If
this happens, use an external degaussing coil.
Slowly move the degaussing coil around the
faceplate of the picture tube and the sides and
front of the receiver. Slowly withdraw the coil
to a distance of about 6 feet before turning
power OFF.
The degaussing coil operates for about 1
second after the power is switched ON. If the
set is moved or turned in a different direction,
the power should be OFF for at least 10
minutes.
If color shading persists, perform the
following Color purity and Convergence
adjustments.
4-3 High voltage Check
CAUTION : There is no high voltage adjustment
on this chassis. The B+ power supply should be
+135 volts (with full color- bar input and normal
picture level).
1. Connect a digital voltmeter to the second
anode of the picture tube.
2. Turn on the TV. Set the Brightness and
Contrast controls to minimum (zero beam
current).
3. Adjust the Brightness and contrast controls to
both extremes. Ensure that the high voltage
does not exceed 32 KV under any conditions.
Samsung Electronics
4-1
Alignment and Adjustments
4-4 RF AGC Adjustment
1. Turn to the strongest local station.
2. Turn the AGC control fully clockwise (VR101, on the MAIN board).
3. Adjust the AGC control until noise (snow) disappears from the screen.
4-5 FOCUS Adjustment
1. Input a black and white signal.
2. Adjust the tuning control for clearest picture.
3. Adjust the FOCUS control for well defined scanning lines in the center area of the screen.
4-6 SCREEN Adjustment
1. Turn to the ACTIVE channel.
2. Adjust the VR screen for a normal picture is (no blooming or flyback line).
3. Adjust the SCREEN control for well defined scanning lines in the center area of the screen.
4-7 Purity Adjustment
1. Warm up the receiver for at least 20 minutes.
2. Plug in the CRT deflection yoke. Tighten the clamp screw.
3. Plug the convergence yoke into the CRT and set it as shown in Fig. 4-1.
4. Input a black and white signal.
5. Fully demagnetize the receiver by using an external degaussing coil.
6. Turn the CONTRAST and BRIGHTNESS controls to maximum.
7. Loosen the clamp screw holding the yoke.
Slide the yoke backward or forward to produce a vertical green belt. (Fig.4-2)
8. Tighten the convergence yoke.
9. Slowly move the deflection yoke forward.
Adjust for the best overall green screen.
10. Temporarily tighten the deflection yoke.
11. Produce blue and red rasters by adjusting the low-light controls. Check for good purity in each field.
12. Tighten the deflection yoke.
4-2
Samsung Electronics
Alignment and Adjustments
4 Pole Magnet
2 POLE
PURITY
2 Pole Magnet
6 Pole Magnet
Clamper
Screw
AD
(V
YOKE
CLAMP
SCREW
6 POLE
CONVERGENCE
4 POLE
CONVERGENCE
Fig. 4-1 Convergence Magnet Assembly
Vertical Green Belt
31m/m
Fig. 4-2 Center Convergence Adjustment
Samsung Electronics
4-3
Alignment and Adjustments
4-8 Center Convergence Adjustment
1. Warm up the receiver for at least 20 minutes.
5. Adjust two tabs of 6-pole magnets:
Superimpose the red and blue lines with the
green. Adjusting the angle affects the vertical
lines, and rotating both magnets affects the
horizontal lines.
2. Adjust the BRIGHTNESS and CONTRAST
controls for a well-defined picture.
3. Adjust the two tabs of the 4-pole magnets:
Change the angle between them.
Superimpose the red and the blue vertical
lines in the center area of the screen.
6. Repeat adjustments 2~4, if necessary.
7. Since the 4-pole and 6-pole magnets interact,
the dot movement is complex (Fig. 4-3).
4. Turn both tabs at the same time, keeping the
angle constant: Superimpose the red and blue
horizontal lines in the center of the screen.
BLUE
RED
RED/BLUE
GREEN
BLUE
RED/BLUE
RED
GREEN
4-Pole Magnet Movement
6-Pole Magnet Movement
Fig 4-3 Center Convergence Adjustment
4-4
Samsung Electronics
Alignment and Adjustments
4-9 Service Mode
1. Enter the Factory Mode. Press the remote-control keys in this sequence:
PICTURE OFF
(RED KEY)
DISPLAY
MENU
MUTE
PICTURE ON
(RED KEY)
2. Use the channel and volume keys (up/down) to move the cursor. Select an alignment parameter.
Use the volume keys (up/down) to adjust the value. Adjustment must be done separately for PAL,
SECAM, NTSC color systems. (As soon as the TV receives a signal, it switches to the correct broadcast
standard.) After adjustments are completed, press the picture off key to exit the Service Mode.
Press the digit keys to directly change channel number.
VIDEO ADJUSTMENT
p1
DEFLECTION
p1
00
RED DRIVE
36
NO CONTROL
PAL
NTSC SECAM
01
BLUE DRIVE
39
00
V-SIZE
-41
-58
02
GREEN DRIVE
32
01
V-SHIFT
3
-10
03
RED CUTOFF
31
02
V-LIN
-5
-4
04
BLUE CUTOFF
28
03
S-COLLECTION
-31
-30
05
GREEN CUTOFF
32
04
EW-WIDTH
65
59
06
SUB BRIGHTNESS
4
05
EW-PARABOLA
12
14
07
SUB CONTRAST
15
06
H-SHIFT
-2
-7
08
SUB COLOR
12
07
EW-TRAPIZIUM
-9
-25
09
PEAK DRIVE LIMIT
63
08
EW-UPPER CORNER
53
39
10
YC DELAY
2 (NTSC)
8 (PAL,SECAM)
09
EW-LOWER CORNER
28
4
10
HOR-EHT
-10
-10
11
SUB TINT
13
11
VER-EHT
-10
-10
12
GAMMA CORRECTION
0
12
BOW
-1
-15
13
ANGLE
-2
-3
Option
p1
Service Mode
p1
00
Plus (12.8 : 9)
Off
Video Adjustment
Deflection
Option
Reset
01
AV Blue Screen
On
02
2-Tuner PIP
Off
03
LNA
Off
04
ATS 1 Run
On
05
Feature Box
9220
Samsung Electronics
4-5
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