A replacement for the HP-41 zebra connector

[james summers]

Successfully installed (second attempt) on a 41CX SN 2406S.

On my first attempt there was no sign of life on replacing the batteries - I think this may have been due to one of the spacing splines shifting slightly as when I replaced the zebra connector as a check I noticed that one of the soldered component leg projections on the motherboard had dented one of the traces on the connector (circled on the picture). Looking at the projection on the motherboard, it did not look particularly severe (circled) and there were no marks on the connector for some of the more severe projections so I assume that the spline had shifted slightly so that it was under the offending projection.

I did find that the splines had a natural bow which tended to cause them to come unstuck form the doubled sided tape holding them in position. On my second attempt, I spent some time flexing the splines to try and remove the bow before reassembly and was rewarded with MEMORY LOST on reinserting the batteries. All keys work, CAT 2 lists the contents of an inserted module and a few trial calculations are all satisfactory.

I used the smaller grey splines which still seem slightly too large but there is only a small gap where the two case halves join at the front (picture with old zebra connector in front). When I first dismantled the 41 I noticed that one front and one rear post were cracked but as I did not have any suitable glue to hand I had to leave them as is for the moment and therefore did not want to tighten the screws any further.

I'll see how the CX performs over the next week and will then try the connector in another 41 and see how it goes.