Drive Belt Replacement; Drive Pulley Adjustment - Sony AV-3600 Service Manual

Fig. 4-2. Lubrication of
capstan bearing
To
lubricate the
Take-Up
Reel
Idler,
remove
the
Tape-Up
Idler Cap.
Apply
a
drop
of
oil
to the
shaft
of
the idler.
Wipe away
excess
oil
from
the rubber
driving surfaces.
Note:
A
lack of
oil
on
this part
sometimes
causes bearing noise
in
Play and
Fast-
Forward
modes.
To
lubricate the Pinch
Roller Bearing,
remove
the
pinch
roller retainer.
Apply
a
few
drops of
oil direct-
ly to the
pinch
roller oil ring.
Sliding Parts. All sliding parts of the tape-transport
mechanism
are lubricated with grease which,
in
normal
use,
need
not be
replenished.
However,
if
new
parts
are installed
or lubrication
is
obviously needed,
apply
a high-temperature grease
at
points of contact.
Avoid
excessive
lubrication.
4-4.
DRIVE-BELT
REPLACEMENT
A
worn
or stretched
drum
drive belt results in
excessive slippage
and
loss
of servo control.
Check the
belt
by
inspecting the inner (bearing)
surface.
Look
for cracks
and
streaks
along the long
dimension
of the
belt.
Replace the
belt
if
it is
badly
scored
along
its
length.
To
check
belt length,
remove
trie
belt
from
the
machine and compare
its
total
lexigth (flattened)
with
that of a
new
belt
from
stock. Replace
the
belt
if it is
^-inch or
more
longer
than
a
new
belt.
To
install
the video-drum
belt,
stand the
VTR
on
its left side.
Loop
the belt over the
motor
pulley,
with
the shiny
side
of
the
belt inside (against the
pulley).
Grasp
the
bottom
of the loop, turn
it
one-half turn clockwise, and wrap around
the pulley
of the rotary head
drum
assembly. See
Fig. 4-3.
motor
pulley
drum
pulley
Fig. 4-3.
Drive
belt
installation
4-5.
DRIVE
PULLEY ADJUSTMENT
The
lower motor
pulley requires adjustment
if
the head-drum
drive belt
slips
off the pulley or
rides
against the
upper
or lower
shoulder of the
pulley. Ad-
just
the pulley
as follows.
Remove
the drive
belt.
Loosen
the
set
screw
on
the
motor
pulley
and
ad-
just
its-
height
by
eye
until
it is
parallel to
the
pulley
on
the rotary-head
drum
assembly.
Reinstall
the
belt-
(See Section
4-4). Place the
VTR
in
the
normal
hori-
zontal
position. Thread and
play the
tape.
Obserre
the position of the
belt
on
the
pulleys.
Stop
tke
machine and
readjust pulley position to
make
tie
belt
run
in the center of
the
pulleys.
Check
final pulley position
by
starting
and
stop-
ping the tape
several times.
Rewind
the tape
and
ty
the fast-forward
mode
a
few
times.
Make
sure
that
the
belt
does not
drift
towards
the edge of the
pulUy
or
slip off
when
changing
speeds.
4-2