question about the HP49g+ F3 and F4 keys

[Steve Simpkin]

(11-30-2018 01:03 PM)grossi Wrote:  Good day to all!

Some years ago I bought an HP 49G+ (my serial begins with CNA515), without testing it a lot, and then I left it it in the drawer. Since now my old HP 48GX begins to have some problems, today I have decided to begin to use it.

However, I have noticed that in my calculator, contrary to all the other keys, the F3 and F4 keys (the central ones under the display) don't click at all and don't give me any touch feedback. They just slightly move, but they don't go down and then up again sharply: I have the confirm of the success of my operation only from the result on the display.

I know about the problems with the old HP 49G and HP 49G+ models, but I am wondering if this particular behavior is a standard "feature" or if it is a problem of my specific unit.
Do you have experienced the same fact on your HP 49G+ calculators?

Can some HP 49G+ owner give me an answer?
Thank you in advance!

I wonder if one or both of the plastic hinges have broken on those two keys?
Early production models of the HP49g+ were known to have a suffered from keyboard issues where the plastic hinge material would break and leave the key sitting loose in the key hole. IIRC the short key life issue was caused by the manufacturer taking the excess plastic left over after forming the keys and melting it back into the plastic used for new keys. This "tempered" the plastic and made it too brittle which caused the key hinge to break prematurely. HP fixed this in later production runs of the HP49g+.