|HP12C with a "funny" ENTER key|
Message #1 Posted by Cristian Arezzini on 5 Mar 2011, 2:10 p.m.
One of the calculators I bought to replace my stolen ones, is a 12C. It's made in USA, serial no. 2906A05016. It's in near mint condition, when I acquired it it had a leaky battery, but I managed to clean everything before any damage was made.
It works very well, the display is clear, and all the keys behave as expected *except* for the ENTER key.
This key works, but its "action" is weird. All the other keys, when pressed, move down about 3mm before reaching the bottom; and only after about 2mm of travel you feel the dome collapsing. They feel quite "soft" at first, then they feel "firmer" just before the dome collapses.
This ENTER key instead, only goes down about 1mm. It doesn't feel "sloppy", and when at rest it's at the same height than the other keys (or possibly a fraction of mm higher). But it feels "firm" from the beginning of the movement; you need more force to get it moving than the other keys. And as soon as it moves, the dome immediately clicks. It almost feels like the dome is already "almost-collapsed" when at rest. As if there's something wedged between the dome and the pin pushing on it. I tried "wiggling" the key around to try dislodging any extraneous material, but nothing happened.
Now, the question: does this description tell something to anyone? What might have happened? And, what should I do, considering that opening a 12C isn't trivial? Should I keep it as it is, or open it to get it to work as intended (if I can)? I intend to use this machine, do you think that using it as it is now could lead to premature failure of that key (though at that age, it might not be defined "premature" anyway)?