JVC TM-R14U Service Manual page 11

TM
-
R 14 U
SUB CONTRAST AND SUB BRIGHT
1
.
Display a color video signal
.
2
.
Set the
cont
.
and bright
to
the
center
clock
positions
.
3
.
Adjust the sub
cont
.
and sub bright for optimum
dis
-
play
.
2
.
Next
,
set
the
SCAN switch
to
NARR
and adjust WIDTH
coil
(
L 505
) so that
raster
is
on
the inside (
about 12 mm ,
from left and right respectively of the end viewable
pic
-
ture
size
.
( Fig
.
K )
3
.
When
raster
is
not
located correctly , adjust H
.
CENTER
VR and repeat steps
1
~
2
.
COMBFILTER
1
.
Display
a
color video signal
.
2
.
Connect an oscilloscope
to
TP
-
42
.
Magnify the color
signal
portions
of the color bar waveform so that the
3.58 MHz elements become
easy to
observe
.
3
.
Adjust T 302 , and minimize the 3.58 MHz elements
.
4
.
Regulate the COMB FILTER VR
to
further minimize
the
3.58 MHz elements
.
5
.
Repeat
steps
3 and 4
to
fully minimize the 3.58 MHz
elements
.
Fig
.
K
95
%
/
/
/
/
Viewable
picture
size
/
/
Raster /
7
/
95 %
Fig . M
/
/
•
HOW TO
CHECK THE HIGH VOLTAGE
HOLD DOWN CIRCUIT
1
.
High voltage hold down circuit
.
After repair of
the high voltage hold down circuit shown
in figure , this circuit shall be checked
to operate
cor
-
rectly
.
2
.
Checking
method of the high voltage hold down circuit
.
(
1
)
Make the short circuiting
across R 917 , 5.1 k £ 7 ,
4
/
1
W , MF resistor ( Refer
to
" ALIGN ' ENT LOCATION
of SCHEMATIC DIAGRAM ) under
normal
operat
-
ing condition
.
(
2
)
Confirm the picture goes
out
.
(
WIDE
)
95 %
95 %
Fig
.
L
HORIZONTAL OSCILLATOR
1
.
Set the H
.
Hold VR
to
the mechanical center position
.
2
.
Connect the jumper clip between
TP
-
33 A and ground
.
3
.
While retaining the H
.
Hold VR , keep
the picture
sta
-
tionary or slowly moving
.
4
.
Remove the jumper wire
.
5
.
Make sure that the
set
maintains horizontal
sync
.
, when
signals are switched
.
3 17 2
\
COLOR SYNC
.
1
.
Input color bar signal .
2
.
Short between TP
-
50 and eath
.
3
.
Connect
TP
-
92 and TP
-
51
by
applying 1 k £ 2
.
4
.
Adjust color
sync
,
by turning TRIMMER capacitor
( C 318 )
.
IC 50 I
I
5
>
-
K
! 4
>
J
R 703
-
VW
—
*
Wv
3 ?
R 704
*
+
+
zz
R 702
az
C 702 D 702
R 70 I
C
70 I
7
m
Tfrr
SUB TINT AND SUB COLOR
1
. Display a color video signal
.
2
.
Set the tint and color controls
to
the
center
click posi -
tions
.
3 .
Adjust the sub ( tint and
sub
-
color for optimum display
.
OOOQOQ OQftOO
1
¥
T 50 I
HVT
I
|
^
| 0 5 0 1 ^
0 6 0 0
t
FOCUS
Adjust focus control for best overall definition
and picture
detail
at
normal brightness and
contrast
.
Fig
.
N
( No
.
5741 ) 11