No keypads are as good as the legacy HP12Cs. But they're too slow. The 30th Anniv edition had great keypad, I loved them, but the calculators were not robust like the old legacy 12Cs.. I've gone through 2ea 30th Anniv editions and won't spend the current $300 asking price for them now. But I found an even better solution!
Solution: buy a new or good used inexpensive12C that uses 2ea CR2032 batteries. Remove the footpads with a blunt knife. Remove the batteries. Remove all the screws with a small jewelers Phillips screwdriver and with the keypad side down carefully unsnap the covers and gently fold the back to the left; careful don't break the wire connections (although I have done and had to resolder them)!
Use two cut two pieces of manilla folder (or better, one piece where the hinge doubles the thickness) to cover the circuit board, placing them over the circuit board just to the right of the wire connections. Size: just under 4" by just over 2", but measure it yourself. What you are doing is putting a backstop to the keyboard, making it much more sensitive to finger pressure. Simply lay the 2 thicknesses over the circuit board and fold the back cover gently on to the front cover and snap back in place. Replace the 6 screws. insert batteries and test it. Put a thin coat of rubber cement on the footpads and replace them.
I've edited this review and this is the step by step with pix:
1. Removing the foot pads
2. There are 6 screws, 1 Smaller and 5 Larger
3. Snapping the case apart
4. Open is to the left as if it had a hinge, careful not to break the wire soldering
5. Cut your manilla folder; I cut it at the hinge so it folds over for two layers
6. Place the cut out on the board. NOTE: a bit of scotch tape helps; be careful to tape it over plastic sections of the circuit board only, not any visible metal circuit board contacts, bcz the glue on the tape may be conductive. Also notice that on this 12C two layers of folder were not enough. The 4, 5, & 6 keys were still not as responsive as my 30th Anniv Edition so I had to add some more thickness to a section of the keys. You’ll only know this if you reassemble and the case and test it. (Of course, don’t cement the footpads until you you’ve screwed the cover back on.) ALSO! Be careful to make sure the LED display is correctly seated or the case won’t snap together on top; you’ll know this bcz the case won’t snap on top near the display when you reassemble.
8. Screw the case together, a bit of rubber cement on the back of the footpads, wait about 10min for them to dry, and you’re good.
9. You’ve just made a $300 30th Anniv edition 12C!
The problem with the latest models is that the factory hasn’t anchored the keypad to the circuit board sufficiently and the keyboard has some ‘slop.’ So, when you press the keys the circuit board ‘gives’ and the keys don’t have a firm backing, so the keys don’t respond. (The older models had several welds between the keypad and the circuit board; the new ones don’t.)
I don’t think the new 12Cs will last as long as the legacy 12Cs, but this is such an inexpensive fix that you can buy these used all day long at a bargain and run them into the ground. This one I picked this one up for $18 used, but new condition. Someone clearly returned it bcz of the key problems. You can make your own $300 12C 30th Anniv cheaply since so many of these are returned and are resold at a bargain
Congrats! You just saved ~$250 or more!
9.22.20 Update: I just did another one that required another layer over the 4, 5, and 6 keys. So I had the two initial layers, plus a third layer over the numbers area. But even that wasn't enough for the 4, 5, and 6 keys. I had to tape an even smaller patch over the 4, 5, 6 area: 4 layers of manilla folder thickness. It works a charm. It feels for all the world like a 30th Anniv edition. So, before you reinstall the footpads, give it good test and if needed, go back in and add another/more layer(s).
