wrote:
I have a Radio Shack Pro-43. My 3
button was not working on the
keypad so I disassembled and cleaned
the circuit board and the back side of
the rubber keypad with rubbing
alchohol. Now most of the keys do
not work. I thought I was cleaning
gunk off the contacts when I probably
cleaned some type of conductive gel
off the keypad.


The stuff most companies use on these pads is similar to the consumer
product commonly called "Liquid Solder." There were two varities, one that
requires heat and a flexable one that doesn't. Obviously, you don't want the
one that requires heat. Sadly, the non-heat flexable stuff is almost
impossible to find anymore (it's also hard to use - hard to spread evenly
over the surface). But I've found a fairly good alternative. The pens used
to repair traces on circuit boards contain conductive inks that seem to work
fairly well on flexable pads. Radio Shack has one called the "Greg
CircuitWriter" conductive ink pen (item 910-3890, special order only). I've
never used this specific product but, if it's typical, put two coats of this
(giving each coat time to dry before the next coat) fully over the center
contact of each pad, being careful not to get it anywhere else on the pad.
This should last almost as long as the original material and can be cleaned
off and replaced if necessary. By the way, if you do find the flexable
Liquid Solder, make sure to use only one very thin coat and spread it
evenly. Good luck.


Dwight Stewart (W5NET)

http://www.qsl.net/w5net/