Re: Problem with IIe keyboard

[dalloff@freenet.columbus.oh.us (Dave Althoff)]

I promised to post this...

If you can't get a solvent to clean your bad keyswitch, here are detailed
instructions for replacing the faulty switch...

A Guide to Replacing Apple ][e Keyswitches
------------------------------------------

By Dave Althoff, ][.  (dalthoff@capital.edu)

NOTE:  This document details the methods I have used to replace Apple 
][e keyswitches.  The procedure is fairly straightforward, but it 
does involve completely disassembling your computer, desoldering the 
old keyswitch, and resoldering the new switch.  If you mess it up, 
damage your computer, hurt yourself, or experience other 
difficulties, I cannot assume any responsibility.  As with any repair 
or modification, proceed at your own risk.

Various comp.sys.apple2 correspondents have reported success with 
cleaning Apple ][e keyswitches.  I have not had much luck with this 
myself, but I have replaced a bunch of the switches in one of my 
][e's.  The procedure is fairly straightforward.  I have been able to 
get replacement keyswitches from Micro Center (Columbus, Ohio) for 
$10/each (Yikes!) for the Alps long-stem switch...which is also used 
in the Macintosh Plus keyboard.  Some ][e's use the Alps short-stem 
key switch with an extension.  If anyone knows a cheaper source for 
these parts, PLEASE let me know!

1.  Turn the computer off, ground yourself to the chassis, then
    pull the plug on the machine.

2.  Invert the computer and remove the Phillips head screws from
    the perimeter.  There are supposed to be three under the front
    edge, and three more along each side edge.  Some may be 
    missing (mine had only four).  Do NOT remove the four smaller
    screws which secure the power supply.  With the screws removed,
    turn the computer right-side up.  Hold it together when you
    do so!

3.  Remove the top of the case.  NOTE:  There are two styles!!
3a.  IF THE KEYBOARD IS NOT ATTACHED TO THE UPPER CASE:
  i.    Set the case lid aside.
  ii.   The keyboard is attached to two supports attached to the
        computer's base pan.  Mark the supports at the edge of the
        keyboard assembly.
  iii.  Note the orientation of the ribbon connector either at the
        edge of the keyboard, or on the motherboard, and unplug
        the ribbon cable.
  iv.   Remove the four screws which secure the keyboard to the
        supports, and remove the keyboard assembly.  Proceed to
        step 4.
3b.  IF THE KEYBOARD IS ATTACHED TO THE UPPER CASE: 
  i.    Note the orientation of the ribbon cable either at the
        edge of the keyboard or on the motherboard, and unplug the
        ribbon cable.  Set the motherboard assembly aside.
  ii.   Remove the four screws which secure the keyboard to the
        upper case and remove the keyboard assembly.  Proceed to
        step 4.

4.  Locate the bad keyswitch, and remove the keycap by pulling
    straight up.  Also remove the keycaps from the surrounding
    keys.

5.  On the bottom of the keyboard, there are two solder points
    beneath each keyswitch.  Locate the solder points for the bad
    keyswitch and COMPLETELY desolder the terminals using some 
    kind of vacuum desoldering tool.  I use a squeeze bulb, but 
    the spring-loaded desoldering tools sometimes work better.
    Be careful not to damage the printed circuit trace...do not
    overheat the joint!

6.  Now for the tough part.  Squeeze together the tabs on either
    side of the keyswitch post, and lift the keyswitch straight
    up out of the keyboard assembly.  If it won't come, then you
    probably don't have all of the solder off of the connection 
    posts.  Or you aren't squeezing the tabs enough.

7.  Align the posts on the bottom of the new keyswitch with the
    holes in the circuit board.  It will only fit one way.
    Press the keyswitch into the keyboard assembly until it 
    snaps into place.

8.  Carefully solder the pins on the keyswitch to the circuit
    board.  Replace the keycaps.

9a.  IF THE KEYBOARD WAS ATTACHED TO THE UPPER CASE:
  i.    Attach the keyboard to the upper case using the four 
        screws.
  ii.   Connect the ribbon cable between the keyboard and the
        motherboard
  iii.  Proceed to step 10.

9b.  IF THE KEYBOARD WAS ATTACHED TO SUPPORTS ATTACHED TO THE
     BASE PLATE:
  i.    Align the edge of the keyboard with the mark you made
        on the support in step 3a(ii).
  ii.   Attach the keyboard to the keyboard support bracket
        using the four screws.  Alignment is very important!
  iii.  Reconect the ribbon cable between the keyboard and the
        motherboard.
  iv.   Proceed to step 10.

10.  Drop the upper case onto the computer base plate, invert
     the unit, and reinstall the screws from the bottom of the
     case.

11.  Reconnect the computer and test the keyboard.  Make sure
     that all of the keys work, in particular the key that you
     replaced.  Also, check all of the keys around the edge of
     the keyboard, particularly the open-apple and tilde, to make
     sure that none of the keys are jamming against the edge of
     the case.

12.  Go enjoy a beverage of your choice, as you have successfully
     repaired your keyboard.  The whole operation should take
     about a half-hour.

--Dave Althoff, ][.
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