JVC HR-D540EE - Servocircuit

2.4 SERVO CIRCUIT
Note: Unless otherwise specified, all test points and adjustments are located on the MAIN board.
VIDEO OUT | R420 ePB 1) Connect an oscilloscope to VIDEO OUT.
(SP SW point) |eMH-2 (stairstep) | 2) Play back the stairstep segment of MH-2 align-
e Trigger slope (—) ment tape.
switching
point
eSP mode 3) Trigger the oscilloscope externally (— slope)
eAUTO with the signal from TP411.
TRACKING 4) Adjust R420 to position the trigger point 6.5
: OFF +0.5H from V. sync.
V. sync OSCILLOSCOPE
re——— 6.6 +0.5 H ——>
Fig. 2-4-1 Switching point
T: 50us/20 mV
TP411
(Trigger)
DRUM FF
Fig. 2-4-2 Oscilloscope
Note: Set VCR to A mode by remote controller,
During playback press the PAUSE button
for “more than 2 seconds” to begin a slow
© SP mede
e@ REC then PB
(slow)
Monitor-TV Presetting
unit
(PTU 94008)
SP slow
tracking
preset
e AUTO motion play back.
TRACKING 1) Set recording video tape into the cassette
: OFF housing.
¢ SOURCE SEL 2) Receive a color broadcast on a VHF-HI chanel
: AUX or supply a color bar signal to VIDEO IN.
3) Record a color broadcast or color bar signal in
the SP mode.
4) Play back recorded signal in the FWD slow
mode and set the tracking control of the
FRONT panel to the center position by sinul-
taneously pressing the (+) and (—) tracking
buttons.
5)
Observe
the
display
on
a
monitor-TV
and
adjust
for
optimum
noise
condition
(best
tracking)
by
depressing
‘‘B
(—)'’
or
““C
(+)
buttons
of
presetting
unit
as
required.
6) Depress the STOP button on the FRONT
panel.
7)
Confirm
that
the
bar
noise
is
not
visible
on
ihe
monitor in the slow mode.
2-4