Commodore 64-sx Keyboard getting stuck?

[Ethan Dicks]

On 7/11/05, Louis Florit <florit at gmail.com> wrote:
> Hi, I pulled out my 64-sx out of the box it's been stored with in
> anticipation of getting my JiffyDos upgrade installed into it.  To my
> dismay, when I plugged it all in and powered it on, the keyboard
> wouldn't work properly.  Any of the keys have to be pressed multiple
> times (3 to 10 times) in order to get the character to show up on
> screen.
> 
> Any suggested remedies?  I'm wondering if the keyboard contacts are
> just a little dirty and need a little cleaning, but I wanted to check
> with the gurus before prying it apart.

Unfortunately, the SX-64 keyboard is made entirely differently than
PET and C-64 keyboards... the SX keyboard is layers of mylar with
printed traces.  The traces have been known to oxidize over time,
rendering the keyboard inert.  You can try to be as careful as you
can, but I have seen plenty of dead keyboards from attempts to repair,
and have never seen a successfully repaired keyboard.  If you manage
to work out a successful technique, please share it with us.  I myself
have two SX-64s, two good keyboards and two dead keyboards (neither by
my hand).

One possible solution would be to wire up an appropriate switch matrix
to a the correct DB25 pinout and completely replace the native SX-64
keyboard.  It would be functional, but not as portable.  I don't want
to say there's zero chance of repairing the original keyboard, but it
would be an accomplishment to do so.

-ethan