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SAFETY PRECAUTIONS
:
An isolation transformer
should be connected
in the power line between
the receiver
and the AC
line before any service
is performed
on the receiver.
X- RADIATION
PRECAUTION
The primary
source
of
X-
RADIATION
in television
receiver
is the picture
tube. The
picture tube is specially
constructed
to limit X- RADIATION
emission.
For continued
X- RADIATION
protection,
the replacement
tube must
be the same
type as the original
including
suffix letter. Excessive
high voltage
may
produce
potentially
hazardous
X-
RADIATION.
To avoid such hazards,
the high voltage
must be maintain
within specified
limit.
Refere
to this service
manual
for
specific high voltage
limits. If high voltage
exceeds
specified
limits, take necessary
corrective
action. Carefully
follow the instructions
for + B1 volt power supply adjustment,
and high voltage
check to maintain
the high voltage
within the specified
limits.
SUB BRIGHTNESS
ADJUSTMENT
1.
Connect
a DC meter
between
"TP - H" (positive
lead) and
"TP - G" (negative
lead) on main unit.
2. Receive
the monochrom
circular pattern.
3. Set
the
brightness
to
maximum
and
the
contrast
to
minimum.
4. Adjust the sub brightness
control (VR211 ) for 0.4 volt.
NOTE:
If the picture tube replaced,
check the sub- brightness
adjustment.
HORIZONTAL
CENTER ADJUSTMENT
1.
Tune
the
receiver
to the monochrome
circular
pattern.
2. Set the brightness
and the contrast
to maximum.
3. Adjust
video
phase(VR411
) for optimum
horizontal
center
position.
TUNING DISPLAY CENTER
ADJUSTMENT
1.
Tune
the receiver
to the
monochrome
circular
pattern.
2. Press
PRESET
switch
(SW713
of the Main
unit), and the
tuning bar is displayed
on the screen,
3. Adjust the tuning bar center
by using VR 791 on the control
unit.
4. Press PRESET
switch.
GREY SCALE AND TRACKING
ADJUSTMENT
1.
Tune
the
receiver
to the monochrome
circular
pattern.
2.
Set the
brightness
and the colour
to normal
,
the
contrast
to maximum.
3. Set the service
switch (SW241
on the Main unit )and SW13B
on the AJV unit) at the service
side.
4. Set
the
drive
volume
(VR681
and
VR661 ) at
their
mechanical
center.
5. Set
the
bias
volume
(VR662,
VR672
and
VR682)
to
minimum
(fully counter
clockwise).
6. Turn the screen
volume
to obtain just visible one coloured
line.
7. Adjust each bias volume
(VR682-
blue, VR672-
green
and
VR662-
red) alternately
until a dim white line produced,
8. Set the service
switch
(SW241
and SW13B)
at the normal
side.
9, Adjust
the drive
volume
(VR681
- blue and VR661
- red)
alternately
to produce
normal black and white picture.
10. Check
for proper
grey
scale
tracking
at all brightness
levels.
NOTE:
If grey scale adjustment
is made after picture
tube
replacement,
check high voltage
and sub- brightness
adjustment.
VERTICAL
LINEALITY ADJUSTMENT
1.
Tune the receiver
to the monochrome
circular ~attern
2. Set the brightness
and contrast
to maximum.
"
3. Adjust VR 461 to be A=B * 3mm.
COLOUR ADJUSTMENT
(PAL~
~eceive
the PAL colour bar pattern(see
Fig.1 )
Set controls:
brightness
and colour :maximum,
ADJUST
REMARKS
—
1
—
2
—
Connect
tl
'R251 ,T28
T211
oscilloscope
to TP13B
of the A/V unit.
Adjust VR251 ,T281
to obtain each 1 H
waveform(amplitude)
for same
as shown
below.
~lHi
$
. . .
Adjust T211 to obtain proper
waveform
as
shown
above.
FOCUS ADJUSTMENT
Adjust focus control on the left side of the chassis
for well
scaning
lines.
VERTICAL
SIZE ADJUSTMENT
1.
Tune
the receiver
to the monochrome
circular
pattern.
2. Adjust vertical
size (VR451 ) control for full scan.
HORIZONTAL
WIDTH ADJUSTMENT
1.
Tune the receiver
to the monochrome
circure pattern.
2. Set the brightness
and the contrast
to maximum.
3. If the picture
is too wide
or narrow,
adjust
the horizontal
width by using VR 481,
Note : Horiz. width adjustment
effects
the high voltage
and
the sub-
brightness.
Therefore,
recheck
the sub-
brightness
and the high voltage.
HIGH VOLTAGE
CHECK
1.
Tune the receiver
to the monochrom
circular pattern.
2, Set the brightness
and the contrast
to minimum..
3, Connect
the high voltage
probe (+) to the anode
lead of the
picture tube and the ground(-).
4, The high voltage
must be less than 35.OKV.
Note:
If the picture tube is replaced,
check the high voltage.
SUB CONTRAST
ADJUSTMENT
1,
Connect
the oscillosco~e
to TP - 6C(+),and
TP - 6E(-
) of the
.,.
CRT unit.
.,
2. Receive
the PAL Colour bar pattern,(see
Fig 1,)
3. Set the colour to minimum.
Set the contrast
to center (on screen
bar:1 6 pos.)
4. Adjust the brightness
or sub-
=
brightness
voiume
(VR211 ) to be
"b=30 * 5V."
5. AdjustVR1202(sub
contrast
volume)
on the video unit to be "a=60 t 2V."
,q!l
w
w
—3—
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