|Re: HP-12c double entries? - A suggestion|
Message #4 Posted by Vieira, Luiz C. (Brazil) on 22 Nov 2002, 11:22 a.m.,
in response to message #3 by Tom Sherman
I faced this sort of problem in many new and earlier HP's, mostly those used in severe environment (open field, dusty atmosphere, etc.).
Each key has it's own contact-plate, and under this plate there is a small, metal-covered hole. This is the way dust gets in, and also the way we pull it out.
I'm gonna try to find the original posts (it's gonna be a bit hard, but...) where a description is made. Anyway, I'll try to describe it my way; please, correct me if I use incorrect terms.
Open the calculator (four screws, each one under each rubber feet) and locate the hole for the repeating key. Allow a small amount of micro-oil (WD 40, White Lub or any better product) to get inside the hole under the key. Thin (very thin) metal wire can be carefully inserted in these holes while the key is released. After that, gently press the key and pull the thin wire out slowly, as you release and press the key again. This will remove any sort of dust.
I myself prefer the painting brush's coats (Gee, is this correct?). It cleans the same way and does not smear the conductive metal.
If it is too much confusing, Ill try to explain in another way.