Radio Shack TRS-80 Service Manual page 14

CASE:
DISASSEMBLY
R5-232 BOARD (optional):
1. Remove all cables hom the bottom and rear of the Com·
puter. Position the Compuler on its rear panel to provide
easy access to the
ca~
bottom. Remove the ten screws
from the case bottom. Notice the different types and
lengths of screws and note their positions. Set them
aside in groups.
2.
Position the Computer upright and remuve Ihe:#6 screw
and washer from Ihe top of the back panel of the case.
3. Very carefully remove case top, lifting striaght up and
setting it aside to the left
(if
facing video screenL Be
careful not to exoeed Ihe length of the video cable.
4.
Remove $Crews from the chassis shield and the ground
connectors and remove the shield .••
CPU BOARD:
1. Remove all cable. connecting thc CPU Board {power
supply cable, video, keyboard, and cassette cables, and
if applicable,
the
RS·232
,md
FDC inter-connect cables).
2. Remove the five screws fastening the PC Board (two in
upper right corner, three on bOltom).
3. Remove the small PCB Mount Bracket and its
two
screws from atop the metal chassis bracket.••
4.
Make sure all cables to the
CPU
Board have been discon,
nected then remove tt'le Board. (If your unit uses plastic
spacer mounts to hold the Board, press the small tOOs on
the mounts through the mounting holes in the PCB and
gently pull the CPU Board off.l
FDC BOARD (optional):
NOTE: The CPU Boarr! must be removl! before removing the
the FDC Board.
1. Be sure to disconnect aU cables to the FDC Boord,
2. Remove the screws holding the FDC Board to the metal
chass.is and remove the Board.
• "Not applicable 10 all units.
NOTE: The CPU Board must be removed before removing
the RS·232 Board.
1. Be sure to remove all cables connecting the RS·232
Bo~rd.
2. R!!move the screws connecting the PC Board to the
chassis and remove the Board.
MAIN POWER SUPPLY:
I , Remove aU interconnect cables to the Boards fastened
on the metal chassis Ixac:ket (power supply cable,
video, keyboard, and cassette cables, and
If
applicable,
RS·232 and FDC power connectors and the Disk ribbo ....
cable).
2. Remove the four screws fastening the metal chassis
bracket to the
case
bottom.
3. Make sure all inter-eonneeting cables arc removed, then
carefully lift out chassis bracket and attached Boards.
4. Remove the four screws fastening the Power Supply to
Ihe Bracket (notice where the ground tab is fastened),
then car.fully remove the power supply,
DISK DRIVE POWER SUPPLY (optional):
1. Disconnect all cables and wires connecting to the Power
Supply.
2. Remove the four screws fa.tcning the Board to the Disk
Mounting Bracket (notice where the ground tab is fas·
tened/. then carefully remove the Power Supply.
DISK DRIVES (optional):
1. To remove the Disk Drive in the top position, carefully
remove the FOC inter·connect cable connected to lhe
rear of the Drive.
2. Remo¥e the fOlK screws and washers (two on ealt'l sidel
which connoct the Drive to the Disk Mounting Bracket.
3, Disconnect the power supply connectOr from the bot·
tom of the top board in the Disk Drive and also remove
the ground wire from the rear of the Drive .
7