JVC HR-D540EE - Audio out

PB switching point
eSymptom: switching noise at
picture bottom.
Lower drum assembly
«Symptoms: Poor FM linearity,
Adjustment and Checks
Checkpoints
VIDEO
OUT
1)
Connect
an
oscilloscope
to
VIDEO
OUT.
2) Set the MH-2 alignment tape into the
cassette housing. Play back the stairstep seg-
ment of MH-2 alignment tape.
3) Trigger the oscilloscope externally (— slope)
with the signal from TP411 (DRUM FF) of
the main board.
4) Adjust R420 to position the trigger point
6.5 H £0.5 H from V. sync as shown in Fig.
1-5-7.
V. sync
Fig. 1-5-7
PB Switching Point
noisy rotation, jitter
*Cause: Lead and bearing wear
Check
FM
linearity
and
swit-
See
above
upper
drum
assembly
items.
ching
point.
Check
control
head
phase
1)
Play
stairstep
signals
of
MH-2
Alignment
Tape. Engage the Tracking Preset mode by
pressing the + and — buttons simultaneously
in the onscreen mode.
(X value)
Symptom: tracking error
PB FM: Main board TP206
DRUM
FF:
Main
board
TP411
Confirm
that
the
same
maximum
FM
waveform level is obtained as when the
tracking is adjusted manually.
2) Refer to the A/C head adjustments.
A/C head
A/C head
5.8mm
Head base
Fig. 1-5-8
Temporary height
ee ey :
T. guide pole
Tape
Screw @
Fig. 1-5-9
Inclination/Azimuth/
Height adj.
Fig. 1-5-10 A/C HEAD position
Set
the
height
as
indicated
in
Fig.
1-5-8
to
fa-
cilitate
tape
transport
checks
and
adustments.
Temporarily set height as indi-
cated in Fig. 1-5-8.
1) Run tape, turn screw @ counterdackwise to
where slight curling of the tape acurs at the
lower flange of the take-up guideroller.
2) Then slowly turn the screw coeckwise to
where the curling ceases.
Tilt (forward inclination)
See Fig. 1-5-9.
(Symptom: audio Sevel varies
greatly.)
Azimuth
1)
Play
stairstep
signal
(with
audic
G
kHz)
of
See Fig. 1-5-9. the MH-2 Alignment Tape. Obes ve audio
(Symptoms: audio low level or output signal with oscilloscope.
noisy) 2) Turn screw @ and adjust for snaximum
Audio output: Main board
AUDIO OUT
audio output level.
1-9