Osborne O1 Keyboard issues

[drlegendre .]

Hi Jules,

Oh, no worries - I'd have taken it in this condition whether or not you
were aware of the issues. After all, it +was+ a gift, and a very generous
one at that; not just in terms of materiel, but in terms of your time
spent, as well.

On the bright side, I may be able to send you some bootable media, if you
still need it. Another kind cctalk'er sent me a pair of bootable O1 discs,
one DBASEII and one WordStar.

I figure I'll go the solvent flush route, using tri-chlor, and see where
that goes. But honestly, I don't know what could be causing so many 'stuck'
keys on this thing! One would hope for (easily clear-able) contaminants,
but it might be more than that. As a previous poster noted, he felt it may
be due to the cord keeping several keys depressed during storage. That
might be worth investigating, if I can find a kb matrix map in the
(incomplete!) service docs.

As ever, my fear is that the materials won't withstand the solvent, even if
it's tri-chlor, and I'll end up washing away every hope of survival. Water
might be OK, but I'd have to grab a couple gals of distilled first.

Ultimately, the dreaded R&R is the option. Not sure if I have the
patience...

-L

On Mon, Aug 24, 2015 at 8:27 PM, Jules Richardson <
jules.richardson99 at gmail.com> wrote:

> On 08/23/2015 03:28 AM, drlegendre . wrote:
>
>> Howdy gents,
>>
>> Working away on the recently acquired Osborne 1. Seems there's something
>> wrong with the KB - and if I didn't know better, I'd say it's a case of
>> shorted contacts.
>>
>> The KB connector is 24 pins, double row header like a short floppy or IDE
>> header.
>>
>> On the KB side, there are two "shorted" groups of pins. Group one is 2X
>> shortred pins, group two is 5X shorted pins.
>>
>
> I just prodded mine with a meter, and the only continuity I get is between
> pins 2 and 23 (numbered as follows, looking into the keyboard connector,
> with the cable exiting toward the right)
>
>  _____________________________________
> | nc 02 03 04 05 06 07 08 09 10 nc nc |
> | nc 14 15 16 17 18 19 20 21 22 23 nc |======
>  -------------------------------------
>
> Thing is, this KB is not really built to be serviced, best as I can tell.
>>
>
> Yeah, I just opened the case on mine, and it's a pretty nasty design -
> cheap as possible :-( Wish I'd tried that keyboard on my system now so you
> knew it had problems!
>
> With such limited access, I don't see many avenues other than flushing with
>> solvent(s) and hoping for the best.
>>
>
> Yeah, I'd do that first - or maybe soapy water followed by a flush with
> distilled, then leave it for a week or so to dry. Can't hurt.
>
> If that doesn't work... break the melted plastic bits off, take the thing
> apart, clean the membrane. Reassemble and put blobs of glue where the
> melted plastic bits were. If you have a drill press, counter-sink the holes
> on the underside of the metal plate first; it'll give the glue more plastic
> to adhere to.
>
> If gluing doesn't work out... urgh. The switch bodies do seem to have a
> little lip around the edges where they rest up against the membrane, so it
> would be possible to slot metal bars down between the rows (secured at
> either end somehow to the metal 'baseplate' below) in order to keep the
> switches from falling out - but it would certainly be a bit of a project!
>
> Nasty keyboard, though! I expect mine will go the same way at some point :/
>
> cheers
>
> Jules
>
>