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HP15C LE Bad Button Presses
08-04-2019, 12:25 AM
Post: #1
HP15C LE Bad Button Presses
I bought 3 HP 15C Limited Editions new back when they were available in 2012. Over the years, all three have been developing a problem with registering spurious button presses.

What happens is I will press a button one time, but it will register two or even three times. If this is a number I can sometimes notice and correct, but if it is an operator it really mess up my whole calculation. It's very tedious.

It seems likely to happen with any button, perhaps 1 out of every 100 presses. It's just now getting bad enough that I can't really use these anymore.

Because it's happening on all three calculators, I assume others have the same issue. However, I did a search and couldn't really find anything. Am I alone? Any ideas?
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08-04-2019, 06:32 PM
Post: #2
RE: HP15C LE Bad Button Presses
(08-04-2019 12:25 AM)RPN_FAN Wrote:  I bought 3 HP 15C Limited Editions new back when they were available in 2012. Over the years, all three have been developing a problem with registering spurious button presses.

What happens is I will press a button one time, but it will register two or even three times. If this is a number I can sometimes notice and correct, but if it is an operator it really mess up my whole calculation. It's very tedious.

It seems likely to happen with any button, perhaps 1 out of every 100 presses. It's just now getting bad enough that I can't really use these anymore.

Because it's happening on all three calculators, I assume others have the same issue. However, I did a search and couldn't really find anything. Am I alone? Any ideas?

I suspect the LE is more of a collector's item for most people. I regularly use the original 15c but hardly ever use the LE.
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08-04-2019, 07:56 PM
Post: #3
RE: HP15C LE Bad Button Presses
I have two of those LE: one in box without batteries for collection, the other bought to be used everyday.
I noticed on this one the same problem with the [7] key. As a consolation, you are not alone.
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08-05-2019, 01:34 AM
Post: #4
RE: HP15C LE Bad Button Presses
That keys bounce problem is also happen to the HP-12C+
I guess that the housing unit construction of the HP-15C LE is from the
same as HP-12C+ the CNA serial#

Gamo
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08-05-2019, 09:28 PM (This post was last modified: 08-05-2019 09:29 PM by BobVA.)
Post: #5
RE: HP15C LE Bad Button Presses
Thomas Radtke suggested in this thread

Thomas Radtke Wrote:The real problem is the hard coded key time-out value. I suspect every 15C LE will once in a while (every couple of hundred keypresses or so) show double registered entries. They appear real fast, so that a slightly higher value would have eliminated this problem

...but if it's getting worse there may be another issue? If it's not mechanical wear on the keyboard - which you'd think wouldn't affect random keys - the only other variable I can think of is lower battery voltage, so perhaps try changing the batteries for fresh ones?
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08-06-2019, 01:43 PM
Post: #6
RE: HP15C LE Bad Button Presses
HP-15C LE keyboard issue was a known problem of the early production units.

Some threads on the issue from the "old" forum:
https://www.hpmuseum.org/cgi-sys/cgiwrap...ead=198408
https://www.hpmuseum.org/cgi-sys/cgiwrap...ead=198814
https://www.hpmuseum.org/cgi-sys/cgiwrap...ead=205539
https://www.hpmuseum.org/cgi-sys/cgiwrap...ead=209159


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08-07-2019, 04:25 AM
Post: #7
RE: HP15C LE Bad Button Presses
(08-04-2019 06:32 PM)Harald Wrote:  I suspect the LE is more of a collector's item for most people. I regularly use the original 15c but hardly ever use the LE.
I share the same view and because I'm not collecting them, I sold my HP15 LE. On the other hand I can hardly imagine someone really uses it for 'real' work.
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08-08-2019, 01:59 PM (This post was last modified: 08-08-2019 09:16 PM by burkhard.)
Post: #8
RE: HP15C LE Bad Button Presses
(08-07-2019 04:25 AM)RMollov Wrote:  
(08-04-2019 06:32 PM)Harald Wrote:  I suspect the LE is more of a collector's item for most people. I regularly use the original 15c but hardly ever use the LE.
I share the same view and because I'm not collecting them, I sold my HP15 LE. On the other hand I can hardly imagine someone really uses it for 'real' work.

Other than some sketchy durability, why would it be hard to imagine anyone using it for "real work"? I've got both a 15C and 15LE. The LE has low use, but works fine. Functionally, it would be fine for "real work", at least until it breaks :-).
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08-08-2019, 02:15 PM
Post: #9
RE: HP15C LE Bad Button Presses
(08-05-2019 09:28 PM)BobVA Wrote:  Thomas Radtke suggested in this thread

Thomas Radtke Wrote:The real problem is the hard coded key time-out value. I suspect every 15C LE will once in a while (every couple of hundred keypresses or so) show double registered entries. They appear real fast, so that a slightly higher value would have eliminated this problem

...but if it's getting worse there may be another issue? If it's not mechanical wear on the keyboard - which you'd think wouldn't affect random keys - the only other variable I can think of is lower battery voltage, so perhaps try changing the batteries for fresh ones?
Thanks for the quote! Yes, there's more than on problem to the 15C LE. Early units (but not all) suffered from some residue. Mine doesn't. But it wouldn't be much of a problem with proper de-bouncing.

I was hoping for either a good firmware to reflash the LE, but Tim was obviously never allowed to release it (if it existed in the first place, that is), or the production of a regular new 15C. Today, all hope is lost.
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08-09-2019, 01:15 AM
Post: #10
RE: HP15C LE Bad Button Presses
Voyager series almost reach it 40 year mark, hope that HP do the 40 year Anniversary Edition again.

Gamo
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08-09-2019, 06:54 AM
Post: #11
RE: HP15C LE Bad Button Presses
(08-09-2019 01:15 AM)Gamo Wrote:  Voyager series almost reach it 40 year mark, hope that HP do the 40 year Anniversary Edition again.

Not a chance, the odds are nill... and NONEXISTENT ;-)
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08-09-2019, 07:59 AM
Post: #12
RE: HP15C LE Bad Button Presses
(08-09-2019 01:15 AM)Gamo Wrote:  Voyager series almost reach it 40 year mark, hope that HP do the 40 year Anniversary Edition again.

And I hope I win a million dollars.

Not going to happen (even if I did buy a ticket...)

I think we all know that HP's calculator swan song is the Prime G2.

There are only 10 types of people in this world. Those who understand binary and those who don't.
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08-09-2019, 08:36 AM (This post was last modified: 08-09-2019 08:37 AM by RMollov.)
Post: #13
RE: HP15C LE Bad Button Presses
(08-08-2019 01:59 PM)burkhard Wrote:  Other than some sketchy durability, why would it be hard to imagine anyone using it for "real work"? I've got both a 15C and 15LE. The LE has low use, but works fine. Functionally, it would be fine for "real work", at least until it breaks :-).
Can I ask you what sort of 'real work' today is worth to be done by any hand-held scientific calculator as opposed to all other means available?
I love (HP) calculators and have quite a few of them, but (as a surveyor) I haven't used one for 'real work' for at least 10 years now. Maybe it's different in other fields... Still strongly doubt it. Any smart phone can do so much more.
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08-09-2019, 01:15 PM
Post: #14
RE: HP15C LE Bad Button Presses
(08-09-2019 08:36 AM)RMollov Wrote:  
(08-08-2019 01:59 PM)burkhard Wrote:  Other than some sketchy durability, why would it be hard to imagine anyone using it for "real work"? I've got both a 15C and 15LE. The LE has low use, but works fine. Functionally, it would be fine for "real work", at least until it breaks :-).
Can I ask you what sort of 'real work' today is worth to be done by any hand-held scientific calculator as opposed to all other means available?
I love (HP) calculators and have quite a few of them, but (as a surveyor) I haven't used one for 'real work' for at least 10 years now. Maybe it's different in other fields... Still strongly doubt it. Any smart phone can do so much more.

Well let's see...General engineering calculations, unit conversions, estimates during meetings, measurement and trig calculations in my wood shop, and (for me) a lot of BINARY↔HEX↔DECIMAL↔BINARY conversions. Yes, I could do all of that on a smart phone, but it wouldn't do it better and, without tactile feedback, I would need to slow down and be very careful with the "button" pushes. And, the smart phone would be tough to read in bright light. Sure I use a phone (well, actually an iPod Touch, rather an iPhone w/o the phone) on occasion for such because it's handy. If I know I'm going to be doing a bunch of calculations, I'll always grab a real calculator, though.
The phone is inferior in every way (except working in the dark).

Now, if I am at work and have something elaborate to do or that I know I'll need to refer back to many times, I'll certainly pull out Excel or even Matlab on my laptop. But often that isn't needed and the calculator is faster and pocketable.
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08-10-2019, 02:51 AM (This post was last modified: 08-10-2019 02:53 AM by Archilog.)
Post: #15
RE: HP15C LE Bad Button Presses
Good evening,

I'm using my HP-15c LE just about twice a week, for any calculation a simple 4-operations calculator could do. It is not a REAL WORK as engineers understand that, but I don't care: it is just important for me as a French teacher and school manager - quite far from scientific daily problems.

If I have to do some more sophisticated calculations - yes, it might occur Smile -, well, I have a good choice, from my HP-21 to my Free42 app and even my 48 calcs - I didn't venture into Prime's or Numwork's dominions but who knows?
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08-10-2019, 07:52 AM (This post was last modified: 08-10-2019 07:53 AM by RMollov.)
Post: #16
RE: HP15C LE Bad Button Presses
(08-10-2019 02:51 AM)Archilog Wrote:  Good evening,

I'm using my HP-15c LE just about twice a week, for any calculation a simple 4-operations calculator could do. It is not a REAL WORK as engineers understand that, but I don't care: it is just important for me as a French teacher and school manager - quite far from scientific daily problems.

If I have to do some more sophisticated calculations - yes, it might occur Smile -, well, I have a good choice, from my HP-21 to my Free42 app and even my 48 calcs - I didn't venture into Prime's or Numwork's dominions but who knows?

Well, sort of my point. I also use HP calcs because I love the touch, the feel and out of nostalgia. Love the big HP32II font, for everything else - HP48GX (black display) and DM42 which I find brilliant with the exception of the keys. Honestly though I can live and do everything I do professionally without them.

Cheers,
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