Sharp VC-780E - Page 20

Vu FOU
| VC-790ET
Adjustment
__When
the
tape
is
above
the
helical
lead.
Supply side guide
roller rotated in
clockwise direction
(lowers guide roller) to
flatten envelope.
Take-up side guide
roller rotated in
clockwise direction
(lowers guide roller) to
flatten envelope.
Figure 1-26.
When
the
tape.is
below
the
helicallead.
|.
|
Supplyside.
.
|
|
Supply side guide
roller rotated in
counterclokwise
direction (raises quide |
roller} to have the tape
float above the helical
iead. The supply side
guide roller is then
rotated jn the
clockwise direction to
flatten the envelope.
Take-up side guide
roller rotated in
counterclociwise. |
direction (raises guide
roller) to have the tape
fioat above the helical ..
lead. _ re
The take-up side guide
roller is then rotated.in. .
the clockwise direction
to flatten the
envelope. —~
d.
Adjust
the
retaining
guide
height
so
that
the
low-
er
flange
of
the
retaining
guide
touches
the
bot-
tom
edge
of
the
tape.
At
that
time,
check
that
the
tape
is
not
curled
nor
wrinkled.
e.
The
X-position
is
adjusted
after
tape
drive
train
adjustment.
Push
the
(+)
and
(-)
tracking
buttons
at
the
same
time
to
set
the
tracking
buttons
to
the
preset
mode,
and
rotate
the
X-position
adjusting
nut
shown
in
Fig.
1-27
with
the
special
bladed
screwdriver
for
maximum
switching
pulse
low
side
envelope,
and
then
adjust
the
A/C
head
position.
Now
adjust
the
play
back
switching
point
to
6.5
+0.5H.
Check
the
flatness
of
envelope
and
sound
by
selfrecording.
X-position
adjusting
nut
Approx. 15 mm
Figure 1-27.
REPLACEMENT
OF
DRUM
ASSEMBLY
20
Removal
.
Remove
the
head
amp.
PWB
from
the
video
head relay board.
-
Remove
the
bottom
board
(Ref.
No
@
in
the
Cabinet
Parts
Diagram).
.
Remove
the
D.D.
drum
motor
connector
(ME).
.
Loosen
the
Drum-base
mounting
screws
@
and
remove
the
drum
ass’y
from
the
mechanism
chassis.
-
Loosen
the
Earth
brush
ass’y
mounting
screw
@
and
remove
the
Earth
brush
ass’y
©.
.
Loosen
the
two
D.D.
motor
rotor
mounting
screws
@
and
remove
the
D.D.
motor
rotor
©.
-
Loosen
the
three
D.D.
motor
stator
mounting
screws
©
and
remove
the
stator
@.
.
Remove
the
two
video
head
relay
board
mounting screws ©
.
Loosen
the
three
drum
ass’y
mounting
screws
©
and
remove
the
drum
ass‘y
from
the
Drum-
base.