Hi Lawrence:
I expected a keyboard problem, since the owner said it had a stuck key.
Sure enough, the boot screen would flash as if you were holding down an
incorrect key.
When I opened it up, the row and column flex connectors were plainly
visible. Also, the keyboard pinout is in the tech ref (which is online, if
you don't already have it).
I peeled a corner of the flex circuit up off the aluminum plate, and could
see metallization crossovers where the shorts likely exist. I could punch
a hole at the crossover to break the short, but then I would need to jumper
the cut traces. And this does not look like a solder job -- liquid
conductive ink perhaps? There could be shorts in the middle of the key
array too. The keyswitches are plastic, with posts that protrude through
the mounting plate, and then melted into place.
All in all a nasty thing to even think about repairing. Perhaps I am on
the wrong track (no pun intended), but I pulled the two flex connectors
out, so the ribbon cable is not connected -- I can measure many shorts
right at the flex terminals. All of the melted-in-place keyswitches would
need to be removed to asses the situation properly. Bummer.
At least I have a new keyboard I can plug in. I have not opened that one
up, so I don't know if it is different.
gil
> Uh-Oh ! I picked up a beige Osborne 1 last summer. It's in my
>lengthening To-Do queue. I booted it at the time but it had a problem
>not recognising the keyboard. I simply figured it was likely a cable
>fault. Now I wonder if there may be larger problems with the
>keyboard. What was your methodology to check the k-b ? I don't
>want to open mine up now to do a visual inspection, lest I be
>captured by the "fix-it" bug and neglect more pressing tasks.
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Received on Tue Nov 19 2002 - 17:48:00 GMT