Teletype 43K001/AAA, Repair Manual

Page: 37 / 82

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To reassemble the early design keytop with hous­
ing:
Insert housing with key; observe position of locat­
ing lug on housing and press into channel. Housing
must snap fully into front and rear channel tines.
To remove the late design RETURN keytop refer
to Page 3-14, on keytop removal for the 50K122
unitized keyboard.
Keytop Spacer
To remove the keytop spacer:
(a) Remove keytop associated with spacer,
and first keytop to the left
(if
present).
(Refer to KEYTOPS.)
(b) Slide spacer to the left as far as it will go
and then pull rearward.
KEYSPACER
Fig. 15-Keytop Spacer Removal
To reassemble the keytop spacer:
(a) Insert spacer from the left and while push­
ing to the right, observe that the spacer
encloses the keytop push rod and the rear
spring.
(b) Replace keytops.
SPRINGS
Keyswitch
(Right View)
SPACER
PUSH ROD
Fig. 16-Keytop Spacer Alignment
MANUAL 525,3-5
Key switches
To remove the key switches:
(a) Remove keytop.
(b) Remove four screws and circuit card
shield.
(c) Remove solder from around terminal pins
of keyswitch to be removed (Fig.17).
�
ll
dl
..l_
SOLDER
.
REMOVED
Fig. 17-Solder Removal
Warning:
Use
a grounded low-wattage solder­
ing iron (avoid prolonged contact with pins)
along with a desoldering tool to prevent damage
to key switch card circuits and components.
(d)
Place 346257 tool over the keyswitch and
press downward. When the tool bottoms
and embossed projections snap into notches on
keyswitch, squeeze and pull back on the tool
to lift keyswitch out (Fig. 18 ).
BASIC
KEY SWITCH
�
Fig.18-Keyswitch Removal
Note: The tines of the tool must pass between
the key switch housing and the inside of the tines
on the channel.