JVC HR-D540EE - Video Circuit

2.5 VIDEO CIRCUIT
Note:
;
Unless
otherwise
specified,
all
test
points
and
adjustment
parts
are
lo
cated
on
the
MAIN
board.
2.
T
indicates
the
time
and
volts
division
setting
of
the
oscilloscope
(Use
10
:
1
probe).
Adjustment
[om
[eons
[AE
[
Sr
REC
color
L201-@
R220
PB
mode
1)
Connect
an
oscilloscope
to
L201-
@
(1C201-
level
and
(VIDEO
UNIT
|
(SP
REC
©
MH-2
color
bar
19)
pin
as
shown
in
Fig.
2-5-1
and
observe
color
ch
balance
board)
color
level)
|@SP
mode
signal
level.
2) Set the MH-2 alignment tape into the cassette
housing, play back the color bar segment of
MH-2 alignment tape.
3) Set the tracking of the FRONT panel to the
Auto tracking off position by simultaneously
pressing the “+” and ‘’—"' tracking buttons.
4) Adjust by pressing the “+’’ and “—’’ track-
ing buttons of the Front panel for maximum
level of the color waveform and make a note of
the higher color level “A’’.
5) Press the STOP button on the FRONT panel
Fig.
2-5-1
Component
view
of
VIDEO
UNIT
board
|
and
eject
the
MH-2
alignment
tape.
©
REC
then
PB 6)
Set
recording
video
cassette
into
the
cassette
e
MH-2
color
level
housing.
Supply a color bar
signal to
VIDEO
IN.
e
AUTO
7)
Trigger
the
oscilloscope
externally
with
the
TRACKING
signal
from
TP411
(DRUM FF) of
the
Main
:
OFF
board. Use (—)
trigger
for
CH1
and (+)
trigger
e
SP
mode
for CH2.
©
SOURCE
SEL 8)
Record a
color
bar
signal
in the
SP
mode.
:
AUX
9)
Play
back
regorded
color bar
signal.
Set
the
tracking of the FRONT panel to the Auto
tracking off position by simultaneously pressing
i
|
the
“+"’
and
‘‘—”
tracking
buttons
andl
confirm
AME | i 85 + 5% of the noted color level at 1C201-19.
If necessary, before recording, adjuit R220 so
that the higher level channel becornes 85 +
5% of the noted level ‘“A’’ during payback as
Fig.
2-5-2
REC
color
level
shwon
in
Fig.
2-5-2.
At
this
time,
confirm
that
. the channel level difference is within 3 dB.
Note: Repeat the above step (9) several iirnes.
2
|
YNR
NC
TP21
R16
eE-E
1)
Supply
a
color
bar
signal
to
VIDEO
IN
and
balance
(IC1-26)
(NC
BAL)
e
SOURCE
SEL:
connect
an
oscilloscope
to
TP21
(I(4-26
pin).
(VIDEO
(VIDEO
AUX
2)
Adjust
R16
for
minimum
DC
step
ditference.
UNIT
board)
|
UNIT
board)
|
e
Color
bar
T:
2ms/5mV
@SP
mode
eAUTO
TRACKING
:
OFF
2-5