HP-41 display problem


My HP-41CV has a display problem.

When displaying an 8, I see either a 9 or an A because the bottom and bottom and bottom left elements are not working. This is true of all 10 positions in the display. In each position, the bottom element is invisible and the bottom left element is often so faint as to be also invisible.

To my surprise, when I press the 8 key I see an A because only the bottom element is invisible. But when I subsequently press the ENTER key, the A changes to a 9 because an additional element disappears.

I have detached and re-attached the CPU at least 40 times and I have also cleaned and examined it thoroughly for broken contacts.

The unit has never been dropped or abused.

Can anyone help me?

Paul S. Natanson paul628@concentric.net Phone +1-908-630-0406 (New Jersey) August 9, 2006.


Check the little links from the keyboard to the display board. Gently pry on each one and see if it pops loose. You might also try cleaning the back of the display with 91%+ isopropyl alcohol. Keep it off the display window... it will leave a white stain behind. If this does not work, the problem is most likely under on of those epoxy blobs and unrepairable (without swapping out the display module).


Some time ago someone (I think it was DW) said that leaving a HP-41 for a long time without batteries could solve this issue. I don't know if it works, but if David's advice does not solve the issue, you can give it a try.

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