Reassembly; Cpu Circuit Board - Radio Shack TRS-80 Service Manual

REASSEMBLY
RS-232 BOARD (optional):
1. Install the PC Board using
#6
x 3/8" screws. If appli-
cable, press the PC Board onto the plastic spacer mounts
then fasten with the screws.
2. Reconnect all cables to the RS-232 Board.
FDC BOARD (optional):
1. Install the PC Board using
#6
x 3/8" screws and the
plastic spacer mounts, if used.
2. Reconnect all cables to the FDC Board.
CPU BOARD:
1. Make sure good insulating washers are attached to the
CPU Board (Rev. F boards only) then fasten the Board
using
#6
x 1 /4"
screws.
2. Reconnect all cables to the CPU Board (power supply
cable, video, keyboard, and cassette cables, and if appli-
cable, RS-232 and FDC inter-connect cables).
3. Attach the small PCB Mount Bracket (if used) to the
metal chassis bracket with two
#6
x 1 /4"
screws.
MAIN POWER SUPPL V:
1. Fasten the Power Supply to the metal chassis bracket
using four
#6
x 1/4" screws. Be sure the ground tab is
fastened back in place.
2. Install the chassis bracket (with all Boards in place) in
the case bottom using four
#6
x 1 /4" screws.
3. Reconnect all cables (power supply, video, keyboard,
and cassette cables, and RS-232 and FDC power cables
and Disk ribbon cable if necessary).
DISK DRIVE (optional):
1. Place the Disk Drive in the bottom position and recon-
nect the ground wire and power supply connector.
2. Fasten the Drive with four
#6
x 1 /2" screws and four
flat washers (two on each side).
3. Reconnect the FDC inter-connect cable to the rear of
the Drive.
4. Position the second Disk Drive in the top position and
reconnect the ground wire and power supply connector.
5. Fasten with four screws and washers (two on each side).
6. Reconnect the FDC inter-connect cable to the rear of
the Drive.
DISK DRIVE POWER SUPPL V (optional):
1.
Before installing the Power Supply, be sure that the
bottom Disk Drive is mounted in place and the Disk
Shield is in positon on the Disk Mounting Bracket.
2. Reconnect all cables and wires to the Power Supply.
3. Fasten the Power Supply with four
#6
x 3/8" screws.
Be sure the ground tab is fastened back in place.
VIDEO MONITOR (CRT) AND VIDEO BOARD:
1. Position the CRT in the Case Top and install the upper
left and lower right
#10
washers and nuts.
2.
Install the upper right and lower left
#10
washers and
nuts. Be sure to reconnect the ground wire from the
CPU cable. It will require two nuts to fasten it.
3. Install the Video Board into the Case and fasten with
two
#6
x
1 /4" screws.
4.
Connect the ground wire with solder lug back to the
Video Board.
5. Install the plug on the rear of the CRT neck.
6. Install the four color coded wires with spade lugs to
their associated terminals (as determined by a colored
dot on the yoke near each terminal).
7. Install the high-voltage anode wire on the side of the
CRT. Use a screwdriver to compress the clip and insert
it into the CRT. Press down on the suction cup to
secure.
CASE:
1. Double-check to be sure all wires are connected cor-
rectly and all Boards are properly fastened.
2. Attach the chassis shield (if used) with
#6
x 1/4"
screws and reconnect the ground connectors.
3. Carefully place the Case Top over the Case Bottom.
Do not hit the CRT neck. It could implode or break
off.
4. Install the
#6
x 3/8" sheet metal screw and flat washer
in the top rear panel of the Case.
5. Carefully rest the Computer on its rear panel and replace
the ten
#8
screws; five 1" sheet metal toward rear, three
7 /8" machine head along front, and two 1" machine
head in remaining positions.
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