Re: IIGS Keyboard Problems

[jp1@aol.com (JP1)]

The IIgs keyboard is notorious for developing an intermittent at the ADB
jack (at the top of the keyboard both sides).  The circuit board design is
such that the socket is held to the board solely by the signal and ground
lead solder joints, and repeated flexing of the jack by mouse motion
and/or by motion of the keyboard can eventually cause one or more of the
joints to become intermittent.

A reasonably valid test is to switch the mouse and keyboard cable plugs to
the 'opposite' jacks and watch for oddball behavior.  If the mouse starts
becoming flaky, you've got the 'classic' problem.

The fix is to resolder the joints might as well do both jacks and while
the jacks are exposed, glue their housings to the circuit board.  It'll be
apparent how a couple of 'dots' of glue where the jack's housing meets the
upper (non-trace) side of the board.  Epoxy is about best to use, but even
something like Elmer's will work.  Silicone rubber is _not_ a good
material to use, unless you have access to the special kind formulated for
use on circuit boards.  (The 'hardware store' variety produces acid that
can harm circuit boards.)

The above-described problem isn't the only thing that _might_ cause the
keyboard malperformance you describe, but it's been known to...often.

Hope this helps.

John P.