[HP-35s] Are bad keys fixable?

[Ron Ross]

A used Hp 17Bii in good shape is very common and inexpensive. True, it doesn't have trig functions, but it is a smaller and better built pocket calculator than an Hp 35s. And it has a better solver, that really allows you to input all the conversions and other features you do need in long variable descriptive names (admittedly, six characters, but 6>1).
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I have a 35s and while I like it, I like it least among my many HPs.