|Re: HP-41 keyboard issue - help from the hardware gurus here|
Message #2 Posted by Geoff Quickfall on 15 Apr 2012, 10:03 p.m.,
in response to message #1 by Geir Isene
Take apart the calc with the usual anti static precautions.
Obtain a small tube of DeOxit gold. Find the pinhole on the circuit side of the keyboard centered on the offending key. This is the centre of of the dome. Introduce a tiny amount of the deoxit into the pore on the circuit side of the dome.
Exercise the key and clean up any fluid forced back out the pore during your key press exercise.
Assemble and test. DeOxit works wonders. Still having a problem? Combine the DeOxit exercise with the following. Secure a stiff fine wire and introduce it through the pore. Swizzle it around and remove it. Introduce the DeOxit.
Reassemble and test.
Typically the key responds perfectly after the DeOxit procedure.
Hope this helps.
I would post a picture but I am not at home at the moment.
Go to this link:
and scroll down the page until you see the tube. If you do not have or cannot get DeOxit try the pin and some denatured alcohol.
Edited: 15 Apr 2012, 10:09 p.m.