HP35 power on (bug?)


Hi ,
first of all sorry if this was posted before. I tried the search engine but could not get any hits on HP35s bug or HP35s ON

Now to my problem.
Can anybody confirm that you can turn on your HP35s by just pressing the "C" button ? No need to press right shift+"C" ?

I also can switch the calculator on by doing the RS+"C" and can switch it off by doing the same.
Should not be, correct way should be LS+"C" but my calculator does it both ways.

Just pressing "C" to turn it on is a problem. I was wondering why I run through the battery's so fast.
Now I suspect I turn on the calculator all the time when I have it in my pocket,bag or else just because the "C" button gets pressed by accident.

Thanks for your help


Mine turns ON with just a press of (only) the C button (the button at the very lower left). I just looked, and if you believe the labelling, it does seem that you should press the blue shift button (what you call RS, I guess) above it first, but I have never done that to turn it on.

This means, of course, that if the calc is off, it will turn on after pressing ANY button(s) (which is ignored because it is off (? with regard to RS)) and then the C button.

Pushing EITHER the pale orange or blue buttons (the ones just above the C button) and then C turns mine off.

I guess you could call this a labelling bug! The button should be labelled C/on and the blue legend on its bottom slope should be OFF.


Thanks Dave,
I thought mine would behave erratic. Honestly I have not recognized this behavior before. Just after the battery was emptied much earlier than I ever would have expected I got curious. The idea to have to press two buttons in a sequence is good thinking for a power key which has to be pressed. My HP50g does have a direct "ON" button and I hate this for the same reasons. Probably that is why I never have catch that the HP35s is supposed to be different.
I carry the HP35s much more around with me, stuffing it in a pocket or have it between my papers for meetings. My HP50G gets more "respect" :-) It is anyway most of the time hooked up by the USB cable to my Computer, so my Battery life is exceptionel.


Just realized something.
Because I am so used to my HP50g I never used the left shift button to shut it down. Always used the (wrong way) right shift "on".
Funny how habits can take you over.
Maybe the behavior is intentionally because it is exactly like the HP50g is doing it. I can just not recall that this is described in the HP35s manual.


The 32SII also can be turned off using either shift key, so the 35s just inherits this mistake. 'ON', however, has been printed in white.


Also just sitting on a shelf, the HP-35s eats batteries significantly faster than any Pioneer or Voyager I know. Similar observation comparing an HP-50G and an HP-48GX. So it's not only the backpack's fault ;-) BTW, all the Voyagers and Pioneers and Charlemagnes have a simple ON key - though a recessed one - and live long with it. So this key is not to blame.



Yes, totally agree, the HP48sx has been my only calculator between 1989 and ~ 2004, I can not recall how often I replaced batteries but it was just a few times. Heck my Ram card has still the original button cell in it ! When I decided to upgrade to the 50g this changed a lot. However the 48sx is compared to the 50g in terms of computing speed no match at all. So I understand why the 50G needs more battery power. However a HP35s empty after 2 month did not sound real. From what I have read it should be more 9 Month or so. I am now paying more attention to how I tread the 35s so let's see what my mileage is on the new set of batteries.


I wasn't talking about an HP-50G *working* versus an HP-48 *working* ... #-I
The comparison is based on shelf-life observations.


Thank-you Walter, also for the edting of the subject


I think there must be different versions of the 35s around... I've had mine for more than 3 years, and it's still on its original batteries. True, I don't use it every single day (like most people here, I share my needs between various calculators) but still, I don't have the "fast discharge" problem often mentioned here...


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