Re: Apple ][+ keyboard

[Nels Bruckner <nelsb@comcast.net>]

On Sep 30, 4:45 am, m...@willegal.net wrote:
> Most likely you have dirty keys, but also make sure you have a good
> ground between the keyboard and the motherboard.  Try a shorter
> ribbon cable, if you have one, or add an extra ground wire between
> the keyboard and the motherboard ground planes.  For more information
> check out my page on Apple II keyboard page.
>
> http://www.willegal.net/appleii/appleii-keyboard.htm
>
> Regards,
> Mike Willegal
>
> On Sep 30, 3:49 am, Nels Bruckner <ne...@comcast.net> wrote:
>
>
>
> > I picked up a really nice looking ][+ last weekend from a local
> > computer recycler.  Inside I found very minimal dust and everything
> > looks to be in good shape; however, the keyboard seems to have a
> > couple functional issues.  I was wondering if these might ring a bell
> > for anyone -
>
> > First issue is there are 4 or 5 keys that don't register at all.
> > These are spread around the board and include the repeat key.  Second
> > issue is that about 50% of the keys that do function are very 'bouncy'
> > - press the key once and you get 3-4 characters on the command line.
>
> > I disassembled and inspected everything, and the keyboard appears
> > visually to be in great shape.  All the copper contacts on the blue
> > fiberglass board are corrosion free (though I cleaned them with
> > isopropal just to be sure), all the metal pads beneath the keys are
> > shiney and new looking, and all the keys function mechanically just
> > like new.  Cleaned the pins on the encoder board, though it also
> > appears to be in like-new shape.  I did not remove and reseat the big
> > socketed chip on the encoder board, because that sucker is IN THERE
> > really tight and I was afraid to pry on it too hard.
>
> > The keyboard behaved identically when plugged into one of my spare ][+
> > boards.
>
> > I've got a Super Encoder on order from Briel, just in case it's an
> > encoder issue.  Unfortunately I don't have another ][ keyboard to try
> > swapping.
>
> > --Nels- Hide quoted text -
>
> - Show quoted text -


     Interesting and very informative page, Mike.

     The keyboard I'm dealing with looks fairly different from the one
on your page (which I'm guessing is from a MUCH earlier ][).  This one
has the detached encoder board (with ctrl/reset two-position switch)
and does not appear to have self-contained key switches, per se.
Rather, each key is a simple mechanical spring plunger that pushes a
thin piece of metal down to bridge two contacts on a separate PCB
below.  The frame containing the keys and the separate board of
contacts are held together with a series of small screws.

     --Nels