"Wayne Tiffany" wrote in message
. com...

"Mark D. Zacharias" wrote in message
t...

Page 50 of the PDF (showing page 77 of the paper manual) shows that the
switches involved are part of a resistive ladder arrangement. Obviously,
a problem with the switches here will cause the stated symptom. I would
look no further than this, except perhaps for some contamination on the
board or switches themselves. We sometimes see this type of thing from
people squirting cleaner directly on the screen - it runs down into the
switches.

Mark Z.

Did a little investigating this weekend and I think the problem with these
switches is in the switches. I measured the resistance to ground as I
pressed the switches and they all wander all over the place depending on
how you press them. I'm surprised they work at all! My guess is
oxidation on the contacts and they don't appear to be disassembleable. I
may live with that one rather than replace all the switches.

WT


Sometimes you can improve the action of the switches considerably by
flushing them with DeOxit.

Mark Z.