HP41.org

My 41cx has been a champ for 40+ years but suddenly the 4 upper toggle keys (on|user prgm|alpha) have become super stiff.

I don't know how they are sprung but something has changed in literally 1 week from working perfect to super stiff. Is this a known issue? I have been searching but the toggle keys are never mentioned.

I've never heard of it. I don't know how all four could start experiencing the same problem at the same time.

Me neither. I was thinking maybe there was some type of foam in there that had gone sticky.

They seem very hard to service. Looks like I would need to drill out all the thermal welds for the keyboard. Perhaps first thing to try is spray some freon in there to clean them.