keyboard problems

[jonnosan <jonnosan@gmail.com>]

On May 13, 4:52 am, "Michael J. Mahon" <mjma...@aol.com> wrote:
>
> A quick way to bypass the keyboard faults and check that most of the
> rest of the machine is working would be to *unplug* the presumeably
> faulty keyboard and connect PB0 to ground.  This is pin 7 of the
> keyboard connector, or pin 2 of the 16-pin game port DIP socket near
> the back of the machine.  Alternatively, if you have a joystick,
> connect it and one of the buttons will be PB0.  Pressing the button
> will be equivalent to *not pressing* the Open-Apple key, and should
> cause the self-test to complete after one cycle, displaying the
> "System OK" message in the middle of the screen.
>
> If this works, as I expect it to, you will need to get a replacement
> //e keyboard to fix your system.
>

I unplugged the keyboard, plugged in a joystick, and held down the
fire button while I turned on the machine. As you surmised, after
about 30 seconds of holding down fire, I got a "system OK" message.

I then had another look at the keyboard, and I realised that the way I
was testing the pins on the keyboard may have actually resulted in all
the keys being pressed - i tried again this morning making sure not to
put any pressure on the keys when I was testing the pins and they
don't seem to be shorted now. So I plugged the keyboard in, and booted
up and I got an "apple //e" message! The disk light also came on and I
assume it was trying to boot off a disk (I don't have a bootable disk
yet - am looking forward to using the bootstrap from 'bare-metal'
feature in ADTPRO at the appropriate time). I tried hitting ctrl-reset
but it did nothing, it kept trying to load a disk.

So I powered down, removed the disk controller and powered up, and got
a "]" prompt.
Most of the keys on the keyboard seem to work, with the following
exceptions:

(on the main keyboard) 3 e h v
(on the numeric keypad) 9 5 -

I can't tell if the apple key or the option key work, since as I
understand they are modifiers for reset which doesn't seem to be doing
anything. Also caps-lock has no visible effect, but shift does.

All of the above is with both the joystick and keyboard plugged in. If
I have only the joystick, or only the keyboard, or neither, the system
still behaves as originally described (i.e. goes into the self-test
mode forever)

> It would also be a good idea to disassemble the faulty keyboard to
> see the inside of the keyswitches--there must be something interesting
> going on in there!  (BTW, the keyboard *has* been completely dry for at
> least a couple of weeks, hasn't it?--just a thought.)
>

How do I do this? I've unscrewed the keyboard from the case, but can't
work out how to disassemble it (how to seperate the keys from the
circuit board), As far as I know the keyboard has been dry.