Message #2 Posted by Vieira, Luiz C. (Brazil) on 9 Nov 2001, 5:31 a.m.,
in response to message #1 by reiner
it seems youll have to open the calculator and start a cleaning procedure. In most situations like this, bad electrical contact between BATT/IO assembly (where batteries make contact and modules are attached to) and motherboard is the like to happen. I would suggest doing this only if you have at least a few previous experience with electronics or calculators. I strongly suggest having a look at http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=2.
In the first photo of the article, you'll see the upper half of the calculator with the BATT/IO assy. Aligned with it, in the lower half, a series of contacts. There MUST exist the best possible electrical contact between them. But I must warn that opening and MOSTLY closing back an HP41 needs careful attention (screw posts, back-case screw holes, etc.)
There are some cleaning procedures I normally use. Sometimes a single swab moisted with alcohol is enough. If not enough, metal polisher (small, small amounts) will clean up the mess. Also, look out for batteries leakage. They are dangerous...
The other possibility runs around the logic board, if yours is a fullnut. If yours is a halfnut (in the article mentioned above, the CX is a fullnut), no logic boards and no other between-boards contacts.
Hope it helps for now. Let us know about your little fella.