41CX halfnut keyboard not responding

[Dave Frederickson]

(12-13-2015 06:10 PM)wojtek Wrote:  I found 41c/cx service manual at http://www.decadecounter.com/vta/pdf2/HP...-90472.pdf
I have only early 41c of 1980 and according to this manual (chapter 3-4) the "satellite" contains Logic PCA. Perhaps on CX there are other circuits there. I have not browsed this document in detail.

That manual and the HP-41C Service Manual can be found on the HP-41 Archive DVD.