Minus-sign on HP34C


Hi there,

I just made a weird discovery: the mantissa of my HP-34C shows negative values with a precessing dot (the one which shines bright, wenn BAT's low), not with the standard horizontal dash.
I have no manual, couldn't find anything in the MoHPC and have currently no access to my MoHPC-CDs.

Could anyone tell me whether this is a feature or a bug? Is the LCD going where only LCDs go? It sure has one or the other segment not working, but this has proven to be a reliable state.

The exponent's minus sign works, though.




First, it isn't a LCD, it is LED! To some people this is blasphemy! :D

If the red dot that shows the low bat lights together with the minus sign, I think that it can be a bad contact or misaligned contact on the display pins - if your calc is that "solderless" version.

Best regards,



Phew, what a BAD BAD slip. Spent to much time mesmerising my 41...

They seem hard to open (at least the people say), so I won't venture this, but as there are funny effects, when I twist ist, this points towards the solderless type.

Again: the minus sign doesn't light at all! When typing in "2 ENTER 3 -", I get ". 1" (the dot being in the upmost quarter of the Light Emitting Diode :-) Display. No MINUS sign at all; same goes with "1 CHS": gives ".1"

I take from your answer, that HP provided the classic dash for negative numbers...



Yes, there is a normal -ve sign on the Spice series, and yes, I think your problem is bad contacts to the display, particularly if this is the solderless version. This is a very common problem

Spice series machines are not hard to open. The procedure has been given here many times, and once you've done a couple, or seen them being taken apart, there's no worry at all.

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