|Re: HP42s sticking key|
Message #5 Posted by Diego Diaz on 2 Feb 2011, 12:16 p.m.,
in response to message #4 by Randy
Just to make sure: Sticky key? or Non-responsive key?
The first symptom is more likely related to the key contacts themselves than to the Keyboard/PCB connection.
Some of the carbon-made contacts turns into dust, creating a weak "contact" between the two conductive foils of the keyboard layers, this weak contact is recognized by the CPU as a permanently pressed key.
Regrettably the only way to fix it is by removing the dozens of plastic rivets which hold the steel frame in place (this is the easy part), then taking the key layers apart, cleaning them and (the *very* difficult part) re-assembly the whole thing keeping a high grade of tightness between the steel frame and the top half.
Sorry for the bad news... I sincerely hope you *only* have a non-responsive key, which in most cases just need the replacement of the sponge beneath the KB contact strip; far more simpler as described by Geoff's article.
PS: I agree: removing the faceplate is not required in most cases.
Edited: 2 Feb 2011, 12:22 p.m.