Main Page | Report this Page
Science Forum Index  »  Electronics - Repair Forum  »  HP 38C calculator disassembly?...
Page 1 of 2    Goto page 1, 2  Next

HP 38C calculator disassembly?...

Author Message
Peabody...
Posted: Tue Oct 27, 2009 12:00 pm
Guest
Has anyone here ever taken apart one of these calculators? My "6"
key is not registering all the time, and I thought I might be able
to clean out the crud in there and make it work again. But it's not
obvious how one would take one of these apart. I've Googled, but
haven't found anything. If anyone has a relevant link, I would
appreciate it.

FWIW, I still think these HPs are wonderful. RPN forever! We don't
need no stinkin "=" key.
 
William Sommerwerck...
Posted: Tue Oct 27, 2009 12:04 pm
Guest
Does the calculator have rubber feet on the back? There are often screws
under the feet.

I had one of the original HP-35s (1972). I'd never heard of RPN, and thought
"What's going on here?" After a few minutes using the calculator, I was
permanently converted. Why would anyone use algebraic entry?
 
propman...
Posted: Tue Oct 27, 2009 12:48 pm
Guest
Peabody wrote:
[quote]Has anyone here ever taken apart one of these calculators? My "6"
key is not registering all the time, and I thought I might be able
to clean out the crud in there and make it work again. But it's not
obvious how one would take one of these apart. I've Googled, but
haven't found anything. If anyone has a relevant link, I would
appreciate it.

FWIW, I still think these HPs are wonderful. RPN forever! We don't
need no stinkin "=" key.


[/quote]
don't see anything specific re: 38c at the following site but it might
give you an idea on how to proceed:


http://www.hpmuseum.org/disasm.htm
 
AZ Nomad...
Posted: Tue Oct 27, 2009 1:40 pm
Guest
On Tue, 27 Oct 2009 11:48:35 -0700, propman <propman at (no spam) nowhere.ca> wrote:
[quote]Peabody wrote:
Has anyone here ever taken apart one of these calculators? My "6"
key is not registering all the time, and I thought I might be able
to clean out the crud in there and make it work again. But it's not
obvious how one would take one of these apart. I've Googled, but
haven't found anything. If anyone has a relevant link, I would
appreciate it.

FWIW, I still think these HPs are wonderful. RPN forever! We don't
need no stinkin "=" key.



don't see anything specific re: 38c at the following site but it might
give you an idea on how to proceed:
[/quote]

[quote]http://www.hpmuseum.org/disasm.htm
[/quote]
HP's are not easy to disassemble. Even with well written directions,
you're still likely to damage or destroy your calculator. I'd suggest
using some contact cleaner to get the crud out. If the membrane
switch is worn out then you're only option is to replace the keyboard
and replacing the entire calculator with a used one is likely to be
cheaper.
 
Charles...
Posted: Tue Oct 27, 2009 4:51 pm
Guest
"William Sommerwerck" <grizzledgeezer at (no spam) comcast.net> wrote in message
news:hc7cq2$hvf$1 at (no spam) news.eternal-september.org...
[quote]Does the calculator have rubber feet on the back? There are often screws
under the feet.

I had one of the original HP-35s (1972). I'd never heard of RPN, and
thought
"What's going on here?" After a few minutes using the calculator, I was
permanently converted. Why would anyone use algebraic entry?
[/quote]
Reverse Polish Notation ... was judged as a racial slur when HP first hit
the market ;>)

Seriously, I was amazed at how easy it was to learn and how many keystrokes
it saved with chain calculations. I am retired and have lost track of RPN
.... is it available in modern calculators?
 
William Sommerwerck...
Posted: Tue Oct 27, 2009 4:58 pm
Guest
[quote]I am retired and have lost track of RPN
... is it available in modern calculators?
[/quote]
HP still sells calculators with RPN. These sometimes include algebraic
notation to simplify the entry of formulas when programming.

It should be noted that almost all "algebraic" calculators are hybrid,
mixing RPN with algebraic entry.
 
Dave Platt...
Posted: Tue Oct 27, 2009 5:15 pm
Guest
In article <hc7th8$lkp$1 at (no spam) news.eternal-september.org>,
Charles <charlesschuler at (no spam) comcast.net> wrote:

[quote]Seriously, I was amazed at how easy it was to learn and how many keystrokes
it saved with chain calculations. I am retired and have lost track of RPN
... is it available in modern calculators?
[/quote]
A fair number of current HP calculator are bi- or tri-lingual - they
support RPN as well as algebraic. The HP12C is RPN-only.

--
Dave Platt <dplatt at (no spam) radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
 
Jeff Liebermann...
Posted: Tue Oct 27, 2009 6:09 pm
Guest
On Tue, 27 Oct 2009 13:00:31 -0500, Peabody
<waybackNO784SPAM44 at (no spam) yahoo.com> wrote:

[quote]Has anyone here ever taken apart one of these calculators?
[/quote]
Yes.

[quote]My "6"
key is not registering all the time, and I thought I might be able
to clean out the crud in there and make it work again.
[/quote]
You're going to have a problem getting the keyboard section apart. The
case comes off easily. Two screws in the battery compartment and it
breaks open. Watch out for the loose IC's. Take photos if you can't
remember the chip directions.

The keyboard is held together by melted plastic blobs. Break them off
and the keyboard section will come apart, but good luck getting it
back together. You're better off immersing the entire assembled
keyboard in some alcohol, and hope that the crud will wash away.
Eventually, the alcohol (and water) will evaporate.

My batting average is about 50%. I've worked over about 4 of the
series (HP31,32,33,37,38...). I fixed keyboards on two but also
destroyed two others. The ones I destroyed were partially working
when I started, and had more dead keys when I was done.

[quote]FWIW, I still think these HPs are wonderful. RPN forever!
[/quote]
Yep. I have a small collection and still use them on a daily basis.

[quote]We don't need no stinkin "=" key.
[/quote]
The HP35s has both Enter and "=" keys (although the "=" key is
somewhat hidden).

--
Jeff Liebermann jeffl at (no spam) cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
iws...
Posted: Tue Oct 27, 2009 9:12 pm
Guest
"Peabody" <waybackNO784SPAM44 at (no spam) yahoo.com> wrote in message
news:2zGFm.11593$86.877 at (no spam) newsfe15.iad...
|snip

| FWIW, I still think these HPs are wonderful. RPN forever! We don't
| need no stinkin "=" key.

Ah yes, RPN vs. algebraic. Kinda the Mac vs PC wars of the 1970's. Or the
Betamax vs. VHS wars of the 1980's.
 
Jeff Liebermann...
Posted: Wed Oct 28, 2009 12:22 am
Guest
On Tue, 27 Oct 2009 20:12:09 -0700, "iws" <nospam at (no spam) nospam.com> wrote:

[quote]"Peabody" <waybackNO784SPAM44 at (no spam) yahoo.com> wrote in message
news:2zGFm.11593$86.877 at (no spam) newsfe15.iad...
|snip

| FWIW, I still think these HPs are wonderful. RPN forever! We don't
| need no stinkin "=" key.

Ah yes, RPN vs. algebraic. Kinda the Mac vs PC wars of the 1970's. Or the
Betamax vs. VHS wars of the 1980's.
[/quote]
Yep.

RPN is better, but there are many more algebraic calculators.
Mac is generally better, but PC's are more common and cheaper.
Beta has better image quality, but VHS didn't have a royalty attached
and is therefore more popular.

Success through mediocrity.


--
Jeff Liebermann jeffl at (no spam) cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
Reinhard Zwirner...
Posted: Wed Oct 28, 2009 12:12 pm
Guest
Jeff Liebermann schrieb:
[quote]
[...]
The HP35s has both Enter and "=" keys (although the "=" key is
somewhat hidden). ^^ ^^
[/quote]

Hi Jeff

Where? I bought my HP35 in 1974 and haven't found this key till now!

Very interested

Reinhard
 
William Sommerwerck...
Posted: Wed Oct 28, 2009 12:23 pm
Guest
[quote]The HP35s has both Enter and "=" keys (although the "=" key
is somewhat hidden).^

Where? I bought my HP35 in 1974 and haven't found this key till now!
[/quote]
He should have said HP-35S. See above.
 
AZ Nomad...
Posted: Wed Oct 28, 2009 1:49 pm
Guest
On Wed, 28 Oct 2009 19:12:51 +0100, Reinhard Zwirner <reinhard_zwirner at (no spam) web.de> wrote:
[quote]Jeff Liebermann schrieb:

[...]
The HP35s has both Enter and "=" keys (although the "=" key is
somewhat hidden). ^^ ^^
[/quote]

[quote]Hi Jeff

Where? I bought my HP35 in 1974 and haven't found this key till now!
[/quote]
HP35s != HP35
 
Reinhard Zwirner...
Posted: Wed Oct 28, 2009 2:15 pm
Guest
AZ Nomad schrieb:
[quote]
On Wed, 28 Oct 2009 19:12:51 +0100, Reinhard Zwirner <reinhard_zwirner at (no spam) web.de> wrote:
Jeff Liebermann schrieb:

[...]
The HP35s has both Enter and "=" keys (although the "=" key is
somewhat hidden). ^^ ^^

Hi Jeff

Where? I bought my HP35 in 1974 and haven't found this key till now!

HP35s != HP35
[/quote]
Many thanks to you and William! I did misinterpret the s as a plural s.
Now I know that there is a HP 35 revival calculator Wink ...

Best regards

Reinhard
 
Jeff Liebermann...
Posted: Wed Oct 28, 2009 6:12 pm
Guest
On Wed, 28 Oct 2009 19:12:51 +0100, Reinhard Zwirner
<reinhard_zwirner at (no spam) web.de> wrote:

[quote]Jeff Liebermann schrieb:

[...]
The HP35s has both Enter and "=" keys (although the "=" key is
somewhat hidden). ^^ ^^

Where? I bought my HP35 in 1974 and haven't found this key till now!
Very interested
Reinhard
[/quote]
The HP35 does NOT have an "=" key. The new and allegedly improved
HP35s does. See:
<http://www.hpcc.org/datafile/V26Special/the35s.pdf>
It's above the +/- key, to the right of the Enter key.

The HP35s was suppose to be an update of the classic HP35 calculator.
Unfortunately, just about everything is different. It's also full of
bugs and annoyances:
<http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=735>
<http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv017.cgi?read=126708>
I use mine effectively, but I'm still disappointed (and disgusted).


--
Jeff Liebermann jeffl at (no spam) cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
 
Page 1 of 2    Goto page 1, 2  Next
All times are GMT - 5 Hours
The time now is Sat Dec 12, 2009 5:42 am