HP-41CV Fullnut CPU-board wanted

[Martin Hepperle]

(02-04-2015 10:25 PM)BobVA Wrote:  If it's got the elastomeric rubber "zebra strip" interconnect, I'd be suspicious of that. They can cause all kinds of strange issues.

If you can possibly swap it for another or, better yet, one of the flex circuit interconnects that might aid your trouble-shooting.

Bob

Bob,

indeed this CV has the usual interconnect with the twin gold plated zebra strips with a sort of silicone core and I examined it carefully. I did some resistance resp. voltage measurements and it seems to work properly, but of course these things are sensitive and I did not verify all connections. The interconnect to the battery compartement also looks fine - no corrosion etc. One of the top screw recesses had broken through and I fixed that. I also tweaked the white elastomeric block inside the battery-keyboard connect a little bit to get more pressure but this did not change anything.
My idea was to first try another board. If this produces the same error, I would probably go the hard route of soldering wires to the connector pads connecting the cpu board with the keyboard. But as this is irreversible, I would like to try a board swap first.

Martin