The keypad switches have a leaf spring that has to buckle
in order for the switch contact to actuate.
Those that make a loud and forceful clunk have sticky grease
that is effectively gluing the leaf to the plastic parts.
If a button doesn't spring, and then suddenly release, as you
press it, it is probably defective.
As a way of visualizing what is happening, the leaf spring has
holders on each of its ends that because the spring is longer
than the space between the holders, force the spring into a
curved "L" shape up against the key plunger, and base. When
you press the key, you are making the space even shorter, and
the spring's curve presses even tighter into the crook of the
"L". When the key's pressure makes it so tight that the spring
cannot move any farther into the crook, the spring pops up,
making a knee, on the bottom of the "L".
If you cannot feel that happen, the spring is either missing, or
is creased. Missing springs will usually be hanging around
somewhere in the front panel area, and can be replaced. Bent
springs can usually be straightened by stroking the crease out
of the spring with a small stick.
Chuck Harris
nojunk@... [hp_agilent_equipment] wrote:
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I have not noticed any dead keys, but I'll run another check. I have some that click with slight force and others that work but don't click.
Thanks, Lamont
