Table of Contents
Advertisement
6. Assemble in reverse order.
7. Turn power
on.
8.
Check for proper operation of both controls.
5.3.3.7 Power Control Switr:h
The power control switch is part of the prime power box. If
it is necessary to replace the switch, the prime power box
must
be
replaced. See paragraph 5.3.2.4 for the Model 1
prime power box replacement procedure or paragraph
5.3.2.5 for the Model 2 prime power box replacement
procedure.
5.3.4 logic Components
5.3.4. 1 Logic Card
1. Turn power off.
2. Pull out on the two handles on plastic card holder to
disengage card from board.
3.
Pull logic card from socket evenly and perpendicular to
logic board.
4. If card is being changed, remove card holder from old
card and install it on new card.
5.
Place card in socket guides.
6. Push card on logic board pins. Do not bend pins. Make
sure card seats firmly, with a snap, in socket.
7. Turn power on.
5.3.4.2 Logic Board
1. Tum
pO\Ner off.
2. Remove all cards from board to
be
replaced, noting
positions.
3. Remove decoupling capacitor from clip, and remove
capacitor wires from the two board pins. Note where
wires were terminated, for later reinstallation.
4. Remove all cables on pin side of board. Cables are
labeled with their pin assignments.
5. Remove plastic bumper (yoke assembly). Check for
presence of Keyboard Feature Jumpers (Diag.
6-10).
Note terminations.
6. Remove voltage buses from board with cables attached.
Note positions for re-installation.
7. Remove all socket-head screws with clamps that hold
board to gate.
8.
Remove board from machine while unplugging connec-
tors plugged in card side of board.
9. Replace in reverse order. Be extremely careful to
replace wires, cables, and connectors on correct board
pins and to replace logic cards in proper sockets.
10. Rewire Keyboard Feature Jumpers onto new board if
feature was present.
5.3.5 Keyboard Components
This section describes procedures to remove and replace
keyboard components. Paragraphs 5.3.5.1 through 5.3.5.5
are common to Type A and Type B keyboard assemblies,
paragraphs 5.3.5.6 through 5.3.5.8 apply only to Type A,
and paragraphs 5.3.5.9 through 5.3.5.11 apply only to
Type B. Ensure that the correct procedure is used. The
following equipment may
be
required:
5-14
Key top puller tool
I sopropyl alcohol
Cloth (lint-free)
PN 9900373 (preferred), PN
75475, or PN 627953
PN 2200200 (or IBM tape
transport cleaner - PN 453511)
PN 2108930 (or tissue - PN
2123106)
5.3.5.1 Keyboard from Display Station
1.
Turn power off.
2. Remove display station front cover.
3.
Disconnect keyboard cable ground strap from
chassi~
4. Remove keyboard cable connector from its socket. 011
Model 2 display stations, I/O cable retainer must be
unhooked to release keyboard connector. On Model 1
display stations, nylon cable clamp must
be
removed.
5. Replace in reverse order
0
6. Ensure that all I/O cable connectors are firmly seated in
sockets and that ground straps are attached.
5.·3.5.2 Keyboard Top Cover
1. Turn keyboard over.
2. loosen the four captive screws in corners of keyboard
bottom pan.
3.
Place keyboard upright on a flat surface.
4.
Lift top cover off keyboard.
5.
Replace in reverse order.
5.3.5.3 Keyboard Assembly from Bottom Pan
1. Disconnect keyboard from display station. (See para-
graph 5.3.5.1.)
2. Remove keyboard top cover. (See paragraph 5.3.5.2.)
3. Disconnect keyboard cable connector.
4. Remove the four fasteners that hold keyboard assembly
to mounts. (Type A assemblies use nuts; Type
B
use
screws.)
5.
Lift keyboard assembly off mounts.
6. Replace in reverse order.
7. Ensure that cable connector is firmly seated.
5.3.5.4 Audible Feedback Assembly
1. Disconnect keyboard from display station. (See para-
graph 5.3.5.1.)
2. Remove keyboard top cover. (See paragraph 5.3.5.2.)
Note: The audible feedback device consists of two assem-
blies. The logic card is removed by pulling it out of its
socket. To remove the audible feedback assembly, proceed
with steps
3
and
4.
3. Disconnect the two
leads from
audible feedback
assembly at connector positions 8 (white wire) and 9
(blue wire). On assemblies where logic card is mounted
horizontally, it is necessary to remove card socket for
access to leads.
4. Remove the two screws that hold relay assembly to
keyboard bottom pan.
5. Replace in reverse order.
Advertisement
Table of Contents
