[comp.sys.mac] Weird keyboard fault

murphy@hao.ucar.edu (Graham Murphy) (01/24/90)

For some time, I have had a problem apparently with my Mac
II's extended keyboard.  The symptoms are that at fairly
random intervals the modifier keys
(caps-lock/shift/control/option/command) are believed by
the system to be stuck down. Usually only some subset of
the five keys gets stuck. I can temporarily get rid of the
problem either by doing an ADBReset or unplugging/plugging
either the keyboard or my trackball.

I have a MacII with an extended keyboard and an Asher
Engineering TrackBall. I have replaced the trackball with
my apple mouse with no change in behaviour. I have used
various combinations of the ADB ports with no change. Unfortunately
I haven't yet had access to another keyboard to test this
most critical part. 

Most annoyingly, the fault is extremely intermittent and I'm
loathe to take the keyboard off for fixing or replacement
until I have the source pinned down more.

Any thoughts would be greatly appreciated.

Graham Murphy


High Altitude Observatory
National Center for Atmospheric Research
P.O. Box 3000, Boulder CO 80307-3000. Ph:(303)497-1565; Fax:(303)497-1137.
INTERNET: murphy@hao.UCAR.EDU; Solar PO: gmurphy@solar.STANFORD.EDU