HP 10c

[KD8TZC]

I have a HP45 (different series than yours though) that was made in 1973 still going strong, as well as a HP16C that was made in 1982 that I still use. I also have a 17BII, which is one of my newer calculators (1999) that is having keyboard problems.

My point is sometimes the age of the unit is not always the culprit, but the quality of the unit, or just plain old luck. I believe that in 1999, the calculators that HP made were still high quality pieces of equipment, but maybe not as high of a quality as the earlier ones, but who knows.