HP15C 'Stuck' in User Mode


Hello All - I hope someone can help,
My husband's HP15C seems to be 'stuck' in the User Mode. The manual states that pressing f+USER keys again will deactivate this mode. Nothing happens when the f+USER key is pressed and USER annunciator continues to display. Anyone have any ideas on how to fix this? Any help would be greatly appreciated. Thx.


Hi Melody,

First, check to see if either of the keys have problems---so try "f" with any other key and make sure it works, e.g. f prefix should clear a prefix, and also show the full "mantissa". And check the RCL key: does it recall a register? If both keys work fine, I would then run a self-check and see what comes up--and then clear the machine if need be (following the manual's instructions).

Good luck and best regards,



Bill's suggestion is a good one, but I just wanted to make sure you are not actually pressing the '+' key. You press the yellow f key and then the RCL key which has 'USER' written in yellow just above it.

Sorry if you already realized this... there is a wide range of experience out there.

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