12 Jul
2005
12 Jul
'05
12:53 a.m.
On 7/11/05, Louis Florit <florit at gmail.com> wrote:
Bletch!!!
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).
Sounds like the infernal DEC LK201... I've never managed to repair one of
those either.
If it's screwed together, or if you can use screws to reasssemble it
after cutting off the heat-stakes (the IBM PC/AT 101-key keyboard is built
this way), then take it apart, clean the contact layers with propan-2-ol.
and pray :-). Most of these keybaords are heat-staked and you can't use
screws (noting to tap into), so you are pretty much stuck.
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
How similar is the matrix to the C64 keyboard?
to say there's zero chance of repairing the
original keyboard, but it
would be an accomplishment to do so.
-ethan
-tony