1984 HP15C rattles


Hi there, hope you've all had a fun weekend.

Some time ago, taking advantage of the temporary price dip on used models when the Limited Edition was introduced, I treated myself to an original HP15C from 1984. When the package arrived, there was a big smile on this old boy.

On the outside, the calculator in mint condition. It passes the tests and works fine.

But when I flip it around or give it a light shake, there is a slight rattle. It is not related to the batteries. Since the body is so clean, I feel uneasy about opening it up, as I'll probably scratch it.

Wondering if others have had the same phenomenon, and would be able to share some insights on what is causing the rattle?

Thanks much!

Wishing you all a beautiful week.


Try putting a folded dish towel, etc, on the keyboard side and gently compressing all the keys, then give it a shake.

Mine has a small amount of key rattle if the keys are free to move.



Hi Bob,

Thanks very much for your suggestion. At first I thought "no way", but I tried it, and sure enough the rattle stopped!

So the keys are rattling.
Are the oldies all like that? No rattle on the limited edition.


IIRC the black keys on the CLE are all attached to a plastic moulding that keeps them in place. The blue and gold keys are not, and apparently did rattle on some machines (though not mine). In contrast, my 12C dating from 2007 has individual black keys. If you turn the machine over slowly, the keys fall forward separately.


What Derek said :-)

If you disassemble a classic 15c you'll have quite a pile of separate keys to deal with. First time I did it I had to hunt up the manual to get them properly re-installed!


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