2.
The
cover
is
attached
to
the
metal
chassis
with
six
screws.
Remove these screws and then flip the cover to the right.
A
convenient
arrangement
for
storing
the
cover/power
supply while working
on
other modules
is
to reattach the
cover/power
supply
to
the
chassis
with
two
screws,
allow-
ing the assembly to rest above the disk drive assembly.
3.
The power supply is attached to the top cover with four
screws.
Remove
the
connectors
attached
to
the
power
supply at the left and then four screws to remove the sup-
ply
completely from the unit.
4.
When reassembling, ensure that the mylar insulator
is
po-
sitioned between the power supply and the top cover to
provide
proper
insulation.
3.5 CATHODE
RAY
TUBE
The CRT is mechanically attached to the metal chassis with
four
screws
which
are
accessible
from
the
front
of
the
unit.
1.
Remove
the
case
rear
terminal
cover,
and
top
cover/power
supply as noted
in
Paragraphs 3.1, 3.2, 3.3, and 3.4. This
allows access to the connections
on
the CRT.
2.
Disconnect the deflection yoke cable from the CRT
PC
board.
3.
Disconnect the connector
on
the rear of the CRT neck
which
is
attached to a small
PC
board.
WARNING
The anode of the CRT may have a high voitage charge.
Before removing the high voltage (anode) iead, discharge
the CRT as follows to prevent a serious shock. Connect
one end of a wire to a known good ground and the other
end of the wire to the metal shaft of
an
insulated-handle
screwdriver.
Insert
the
screwdriver
blade
under
the
suction
cup and touch it to the clip holding the high voltage lead.
4.
Disconnect the high voltage lead by inserting a grounded
screwdriver
under
the
cup.
Use
the
screwdriver
to
com-
press the clip and pull the wire tree.
5.
Disconnect fhe ground wire (fastened
at
the splice) to the
CRT neck connector PCB.
CAUTION:
If
the CRT is dropped,
it
may implode.
To
avoid this kind of
accident, carefully support the CRT when removing
it
from
the chassis. Do not handle the CRT by the neck
as
this
may cause the tube to break and cause
perso"al injury.
14
6.
Remove
the
four
screws
and
washer
from
the
front
of
the
CRT which attach
it
to the metal chassis. Carefully slide the
CRT out of the chassis through the front.
3.6 SWEEP BOARD
The CRT Sweep Board
is
accessible after the Ci;lT IS removed
from the unit.
It
is
mounted to the left side of the metal chassis
with four screws.
An
insulated plate is located between the PCB
and
the
metal chassis. Make
sure
this
plate
is
in
place
on
reassembly.
3.7 MAIN LOGIC PCB
The main logic PCB is a large board nested inside a metal pan
at
the
bottom
of
the
main
metal
chassis.
To
gain
access
to
this
assembly, remove unit parts as noted
in
Paragraphs
3.1
and
3.2.
It
is
not necessary to remove the power supply assembly,
or the CRT and associated PCB. Remove
all
connectors
at
the
rear of the unit. These include the Modem connector, I/O port
edge-card connector, printer edge-card connector, and floppy
disk edge-card connector.
1.
There
are
four
screws
on each
side
of the metal PCB
mounting pan which attach the pan to the metal chassis.
Remove
these
screws
and
the
board
and
pan
can
be
re-
moved
as
a
sUbassembly
from
the
chassis.
2.
At
the front of the board, remove the four connectors
at
the
left front of the board. These include the reset, video,
and
power
connectors,
and
a
grounding
wire.
3.
Nine screws attach the main logic PCB to the metal pan.
The board is spaced away from the pan with raised bosses
stamped into the pan.
3.8 KEYBOARD ASSEMBLY
1.
The keyboard assembly is attached to the Main Logic PCB
with a connector located at the right rear of the board. The
PCB must be removed from the pan to allow this connector
to be removed. Therefore, disassembly procedures for the
main PCB must be followed.
2.
The keyboard assembly
is
disassembled by removing the
7 mounting screws from the underside of the assembly.
One
of
these
screws
is
under
a
cork
non-skid
strip
and
care
should be taken
in
removing this strip so that
it
is
not ripped
or punctured.
3.
Remove the top cover, lift the keyboard PCB from its po-
sitioning
bosses,
and
then
remove
the
keyboard
connector.
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