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Open the front panel.
Remove
the shoulder screw that attaches the door- support bail to the left chassis
wall.
Note
that
there
is
a nylon
washer
between the
bail
and
chassis
wall
to
prevent scraping.
Turn the chassis so that the left wall is facing you. Remove the left rack flange
by removing the six unrecessed screws.
Remove
the
three
screws
that
attach
the
rear
panel
to
the
main ( steel)
side
panel.
Remove
the
remaining six
screws
and
gently lift
off
the
side
panel
by
pulling
outward.
****
This procedure is directly reversible with cautions:
Position the steel side panel and start, but do not tighten, all nine screws.
Observe
the
areas
where
the
flanges
meet
the
rear
panel
and
internal
bulkhead,
and
align
the
flanges
so
that
the
covers
will
seat
on
a flat
mounting surface.
e)
Removal
Of
Card / PS ( The
DC
Regulator) From
Rear
Panel
And Power
Transistor Replacement: Because the removal procedure is complex, this card was
designed to permit many servicing operations to be performed without removing the
card from the chassis.
IC's
are
conventionally
socketed.
Many
unsocketed
components
can
be
replaced
from the topside by tack- soldering the new component to the lead stubs of the old
clipped- out component.
If the card must be removed, do it as follows:
CAUTION
The
rear
panel
serves
as
a heat
dissipator
for
the
power
transistors.
Proper contact is necessary to insure sufficient transistor cooling. Please
follow instructions carefully.
Remove
the
four
press- fit plastic plugs on the power transistor covers with a
pair
of
chain- noise
pliers.
This
will
reveal
the
transistor
mounting
screws.
Remove the four screws holding the power transistors.
VERY
carefully and slowly pull
each transistor from
its socket. If,
as
you
do
this, the silicone rubber insulator tends to stick to the panel, release it from the
panel
such
that
it
sticks
to
the
bottom
of
the
transistor
instead.
After
you
remove each transistor, press its insulator back in close contact with it pending
reinstallation.
NOTE
These
insulators
form
themselves
to
the
bottom
surface
of
each
transistor. Since they take a " set", they should not be interchanged
or reversed. If you have to replace a power transistor, you may re-
use
the
insulator if it is in good condition. With care, it will re-
form
itself
as
necessary.
Otherwise,
use
a conventional
mica
insulator and white silicone heat- conducting compound.
C-3
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