Audible Alarm; I Keyboard Units; Keyboard From Display Station; Keyboard Top Cover - IBM 3279 2A Maintenance Information

4.10 Audible Alann
1. Switch power off and remove the mainline
power cable from the power socket.
2.
Remove. the analog card as detailed in section
4.5.4.
3.
Remove the two screws that secure the audible
alarm assembly to the base of the enclosure (see
Fi8ure 4-10).
4.. Note the position of the five wires connected to
the audible alarm assembly by push-in
connectors (see Figure 4-10).
5. Lift the audible alarm assembly, remove the five
connectors and withdraw the alarm f ... m the
display.
6. Reinstall the audible alarm assembly in the
reverse sequence.
To Alarm Potentiometer
'------+-r-SCrews
Figure 4-10. Audible Alann Assembly.
4.11 Keyboard Units
4.11.1 Keyboard From Display Statioll
1. Tum power off.
2. Open the customer access panel at the rear of
the display.
3. Remove the wing nut that holds the keyboard
cable to the frame.
4. Free the cable clamp, and remove the keyboard
cable connector from its socket.
5. ReinstaU in the reverse sequence.
6. Ensure that aU cable connectors ·are ·tightly
seated in the sockets and that the ground straps
are attached.
3279 MIM
4.11.2 Keyboard Top Coper
I. Invert the keyboard.
2. Remove the four screws in the comers of the
keyboard base.
3. Place the keyboard base on a flat surface.
4. Lift the top cover off the keyboard.
5. Reinstall in the reverse sequence.
NOle:
Check for cover clearance around the keys
after the cover has been reinstal/ed. Adjust if
required.
4.11.1 Keyboard Assembly From Base
1. Disconnect the keyboard from the display
station (see section 4.11.1).
2. Remove the keyboard top cover (see section
4.11.2).
3. Disconnect the keyboard cable connector and
clicker connector at the logic card.
4. Remove the two screws that hold the keyboard
assembly to the base (mark for alignment
reference).
5. Handle the keyboard assembly by the sides and
lift it off the base, taking care not to press any
keys.
6. Reinstall in the reverse sequence.
7. Ensure that the cable connector is tightly seated.
4.11.4 Clicker A.ssembly
1. Disconnect the keyboard from the display
station (see section 4. II. I).
2. Remove the keyboard top cover (see section
4.11.2).
3. Disconnect the· clicker_connector.
4. Remove the clicker assembly by sliding the bail
fastener from under the cast tabs.
S. Reinstall in the reverse sequence.
4.11.5 Keybllttoll
Keybuttons are removed by sliding the key top puUer
over the key top and pulling straight up.
Chapter 4. Removal and Replacement Procedures 4-11