Looking for HP41CX Advice

[GreyUser]

If your 1 and 3 keys has the same travel and click as the other keys, it is a probably a later production model where they must have changed the tolerances. It’s important to never over-tighten the nuts that secure the cpu board, it will reduce the 1-3 key travel and you’ll notice it. Ultimately, the fix is to abandon the nuts altogether and use the later design spacers over the posts to apply pressure on the cpu board from the case back.

If you choose to use spacers, which IMO is the best overall solution, you can fab them yourself from styrene stock available in hobby stores. When doing this, you must insure the lower case screws are 3/8” long, not the original 1/4”. The shorter screws will absolutely strip out and they also lead to low post fractures. On any 41C that I repaired that had nuts, I never put them back on, I installed spacers. HP had different size nuts for posts that had stripped but I always thought it was just bad solution chasing a bad design.

As for 1-3 tall key issue, I’ve never been able figure out the exact cause, other than for over-tightening the nuts. I’ve found that some machines just will never have the proper travel or feel, no matter what you do and others seem to be fine. The only correlation I’ve found is that the older the s/n, the more likely it will have the two keys without the usual travel and click feel.

Of all the HP keyboards, my favorite would be the 41. Best combination of travel and tactile feedback. After almost fifty years of HP use, I haven’t decided if I prefer the basic function keys on the left side or the right.