Teletype 43K001/AAA, Руководство по ремонту, Страница: 46 / 82

525, 3-14
C. DISASSEMBLY/REASSEMBLY (Contd)
2. 50K122 UNITIZED KEYBOARD (Contd)
To remove RETURN keytop:
(a) Remove a minimual number of the sur­
rounding keytops to allow the RETURN
keytop to be grasped
v
·ith the fingers. Remove
by pulling up (Fig. 42).
Fig. 42-Return Keytop Removal
For removal of data and control keytops, refer to
Page 3-3 Keytop Removal for the 43K101 Key­
board.
Circuit Card
To remove the circuit card:
(a) Support the keyboard bottom side up so
that the keytops are not depressed.
(b) Remove the five screws that secure the
bottom pan to the keyswitch housing
assembly (Fig. 43).
(c) Remove the five screws that secure the
insulator and circuit card to the keyswitch
housing assembly (Fig. 43).
Warning: Once the circuit card is removed, main­
tain the key tops in the undepressed state. Depress­
ing a keytop will dislodge the key plunger mecha­
nism. Also, the cams of the latching keyswitches
may fall out of engagement with the housing if
the keyboard is positioned bottom side down.
Refer to Page 3-16 for recommended holding fix­
tures for 50K122 keyboard disassembly.
SELF TAPPING
SCREWS
( 5 Places)
------
,
I
I
I
BOTTOM
PAN
Fig. 43-Gircuit Card Removal
Keyswitches
To remove the data keyswitch assembly:
(a) With the circuit card assembly removed,
depress the keytop of the plunger mecha­
nism to be removed. The lower plunger assem­
bly will disengage with the housing and can be
removed. (Fig. 44).
Note: Once the lower plunger has been removed
take care not to misplace the air gap spacer and
magnet which lie in the housing assembly.
LOWER
PLUNGER
Fig. 44-Lower Plunger Removal