Help with credits in the book, please.



#19

Hello all!

The book is comming along well, of course that is a subjective opinion since I have never written something this large for publication.

Just finished the Pioneer and Stretch Pioneer chapter which gives the following examples:

1.  HP 48SX with non functional display and keyboard
2. HP 42S with non functional display, keyboard and the memory
upgrade.

Here are some unlabled pictures of the 42S restoration and memory upgrade. All this thanks to Tony Duells' postings and emails. The book has many more figures, each referred to in the text and much more helpful then what is pictured below.

Removing the keyboard overlay for access to the four heat stakes.

Two keyboard overlays, one with the adhesive and curved from
removal, the other with the adhesive removed and reshaped by placing between two vinyl sheets and flattening with a spoon.

Close up of the heat stakes before drilling.

Close up of the heat stakes after drilling.

The deteriorated keyboard flex PCB foam insert. The major cause
of the failed keyboards on the Pioneers and Stretch Pioneers.

Jumper desoldered showing the trace bridge left after the solder
was removed

Close up of the jumper with the trace bridge removed and new jumper
in place.

New memory accessable!

_______________________________
-------------------------------

Now for the reason and title of the post. There are THOUSANDS of postings in the archives ;-). Also articles and repair sections of the museum, let along googling the internet for repair techniques.

I certainly do not want to step on any feet when it comes to credit for techniques that have been developed. With that in mind I am compiling a list of peoples names that seem to be the originators of various techniques.

Some obvious names come to mind:

1.  Katie Wasserman and the HP-97 topcat printer gear replacement
2. Tony Duell and the increase of RAM for the HP42s
Tony also came up with a milled brass pinch roller for the 41C!
3. Diego Diazs' flex PCB replacement for HP 41C I/O assembly.

But some are not so obvious:

3. Vinyl tubing for pinch roller
4. Dampening couple using wire insulation
5. Jumper position in the Spice for decimal versus comma separator
6. Foam insert replacements for Pioneers.
7. Just saw Luizs' spice wire work around for broken flex PCB
8. Using vinyl envelopes to smooth out labels that have been
removed from the backs of the Classics and others.
9. First occurrence of the quartz crystal application to the
HP-45.
10. LED block replacements for removing ghosting. Did this one
after reading the forum and resurrected an HP-45 and HP-80.

The problem is the proper crediting of techniques. Of course a blanket THANK YOU would suffice but I rather be more personal.

For those of you wondering why the book is taking a while; it is going to be 300-400 pages with over 250 figures. It encompasses all the techniques that have been published (hopefully).

I am, however, documenting ALL the restorations in house and this takes time. For example, I need a Spike for photo purposes. I have one being lent to me but I have to get to London to pick it up (thanks Wlodek).

As you see above, I just finished upgrading 3 HP-42S to 32K. Two were non functional off Ebay and once I had documented the successful conversion I then upgraded my HP-42s that I use along with my HP-41C.

So does anyone know who originated the following:

1. Vinyl tubing for pinch roller.
2. Dampening couple using wire insulation.
3. Jumper position in the Spice for decimal versus comma separator
4. Foam insert replacements for Pioneers.
5. Just saw Luizs' spice wire work around for broken flex PCB.
6. Using vinyl envelopes to smooth out labels that have been
removed from the backs of the Classics and others.
7. First occurrence of the quartz crystal application to the
HP-45.
8. LED block replacements for removing ghosting. Did this one
after reading the forum and resurrected an HP-45 and HP-80.

Cheers, Geoff

Edited: 16 Oct 2009, 7:14 p.m.


#20

Hello Geoff!

When you talk about opening a Pioneer series calc you mean drilling the 4 stakes?

I have opened several Pioneer and never in a so intrusive way.

I mean, drilling damages too much and removing an overlay is very dangerous (aesthetically).

Hope my opinion doesn't bother you.

REGARDS


#21

I am not happy with just fixing the calculator but actually restoring it to the original factory look.

With that in mind, how do you open your Pioneers?

I have used two published techiques. The 'carefully pull apart and hope technique' and the 'careful removal of keyboard overlay' technique, then drill a miniscule amount of the stakes.

Both these techniques were successful, however, the pull apart version does distort the keyboard and mylar film and can cause several stressful moments as well as damage to the stakes and electronics if done incorrectly. It is also not as controllable as the keyboard overlay removal.

The careful application of heat to soften the adhesive and gentle pulling will remove the overlay without damaging it is the secret. The technique of removing the adhesive with adhesive remover and then flattening the overlay by rubbing it with a spoon while sandwiched between two sheets of vinyl has restored the overlay to perfect condition. It then is a simple process of gluing the overlay back into position.

All three 42S that I just did were using the keyboard overlay removal. Also, the stakes are drilled just enough to allow the shells to separate with some force but definitely less then the pry apart techniqe described. This allows the keyboard to be reapplied and the shells to snap back together. Also this allows continued access to the insides if done correctly. With the cautious application of drilling the shells will actually snap back together tightly.

I have successfully opened the Pioneer series and Stretch Pioneers series by removing the keyboard overlay (actually quite easy) without damaging them.

I have also opened them by carefully prying the heat stakes apart (much harder). I prefer the overlay technique described to me by Tony Duell.

After regluing the overlay back in place, all three calculators look perfect. The added bonus of having the overlay off is the ability to clean the keys of debris and the overlay. It also allows one to touch up the overlay with paint if required prior to replacing it.

Unless you have a third option (secret?) I recommend the removal of the overlay and the drilling of a very miniscule amount of the heat stakes versus the prying apart of the calculator with force. This is of course explained in the book as all techniques are included.

By the way I have restored six 48s and four 42s, a 32S and a 32SII and all look brand new.

Hope this explains the technique a little more, for a full explanation you will have to wait for the book.

Cheers, Geoff


#22

Hello Geoff,

Thanks for the explanation!

I have to say that I like very very much the way you restore the calcs, they look very nice and new.

I surely will buy the book.

I have opened several 48 series ( mem upgrade ) in my university years and repaired some and replacing original ( blue LCD to black LCD ) parts from 49 bad working units.

I'm not a perfectionist like you! but the way I open calcs has never damaged any calc.

the first time I opened a 48 I did the way you are telling here and I destroyed the overlay...

So I searched and found other ways.

It is true that the way of pulling creates more stress.

I open the calcs with 3 or 4 credit cards, these plastic cards don't damage the body of the card, and little by little it is possible to pull the stakes.

After that the calcs don't look opened.

And if the calcs in case of 48 series are singapore or USA versions ( stronger than indonesia ones ) I use a metal credit card.

REGARDS

Edited: 16 Oct 2009, 8:08 p.m.


#23

Thanks again!

You just cleared up a question I had as I remember reading about your credit card use for opening the case.

I actually tried this on a 48SX which needed a new foam insert. Unfortunately it took hours on my particular calculator (U.S.) and it was extremely tough. It was not the technique but the calculator I am sure!

In any case both methods are explained and your use of the credit card (hotel key?) is excellent. I was using peg wood for the same reason, so the calculator would not be damaged.

In any case, I still prefer the keyboard overlay method if done correctly, but thats me! And the minimalist drilling of the stakes.

Cheers, Geoff


#24

Geoff,

I think that giving specific credit is hard to do as many repair ideas were hashed out here over the years by many people with much back and forth dialog. I think a blanket credit to the Museum Forum members and especially Dave Hicks for facilitating all this would do nicely.

-Katie


#25

Thanks Katie,

I would tend to agree but as with cases such as the topcat printer the cudos are obvious ;-)

After all provenance for discoveries is an on going thing, just look at my field (Botany/Forestry) names of plants keep changing as an earlier paper is discovered describing a certain species.

So a blanket thankyou (already typed it out in the intro) should suffice. Any other ideas!!

Cheers, Geoff

#26

Hello Geoff

Have you ever read these before?

Upgrading the memory of the HP 42S to 32K, Crystal resonator replacement for double speed 42S

Repairing the HP 32sII with faulty keypad


Regards,
Lyuka


#27

Lyuka,

Thanks and yes, they are beautifully documented and photographed. However the dates of 2008 and 2007 were not the first occurences of these repairs.

Tony Duells description goes back to a Datafile more then 5 years back. I repaired many calculators prior to the postings above.

This is no way takes away the value of the postings done by Takayuki Hosoda but creates the question; Who created the idea?

As Katie stated, many of the repair and restoration techniques were a group effort over many years. I am attempting to almagamate all the techniques into one book as they apply to each family (chapter).

Thanks again for the feedback.

Geoff


#28

Hi, Geoff;

first of all, congratulations on your writings. I am sure the book IS already a must-read.

Second, I remember that the first time I saw a reference at the MoHPC Forum about the jumper in the Spices´ power-supply board to select comma or dot as radix mark was in a post by Katie Wasserman. Later I took a picture myself and posted again, but this time it was a power-supply board with a different layout. I have both pictures stored in my computers. They are about eight years old... give it or take.

About any of my contributions you believe that may help in your book: crediting Dave Hicks and/or the MoHPC suffice, mostly because my contributions are here only for they found shelter.

Cheers.

Luiz (Brazil)

P.S. Thanks for your suggestions regarding Topcats´ battery pack... I appreciate 8^)

Edited: 17 Oct 2009, 12:50 a.m.


#29

Quote:
Second, I remember that the first time I saw a reference at the MoHPC Forum about the jumper in the Spices´ power-supply board to select comma or dot as radix mark was in a post by Katie Wasserman. Later I took a picture myself and posted again, but this time it was a power-supply board with a different layout. I have both pictures stored in my computers. They are about eight years old... give it or take.

If I can add a further theory or info to this one please because I have not yet seen or heard about a Spice that breaks the theory.

I posted this before and was given a different explanation but logically, that explanation does not ring true to me.

I very strongly suspect that any Spice that has an asterisk next to the serial number is factory set to show a comma radix. Whilst this isn't a repair issue, if the theory is correct at least it lets you know what you are getting if you aren't able to confirm before hand.

My sample is small, slightly more than 10 calcs but none have broken the rule so far.

Anyway, just throwing that in whilst this aspects of the Spices is topical.

Mark

#30

Hi Luis,

I have an extra Spice that I use as a test bed and guinea pig that I'd like to change the radix from period to comma. I do remember a post that showed how to do this by cutting a particular jumper on the power circuit board, but have lost the link. If you have it, could you post it. Thanks.

Regards, Michael


#31

Hi, Michael;

of course, no problem. Just let me find the pics and I'm posting right away (I have six PC´s and 14 HD´s, but I am sure the pics are in one of two of them... Fingers crossed!)

Cheers.

Luiz (Brazil)

#32

That was fast! Just sit in front of the computer, plugged the pendrive, opened the first suspicious directory and... there it is!

This image was captured with a flatbed scanner and shows the jumper for comma/dot selection in Spice series calculators. This is the power supply board of an HP38C, and chances are it is common to all other C-type Spices. This picture was (careless, sorry for the lack of focus...) taken a few minutes ago with a digital camera and shows the jumper for comma/dot selection in E-Spice series calculators. This is the power supply board of an HP38E, and maybe it is also common to all other E-type Spices.

Hope these help.

Luiz (Brazil)


Edited: 23 Oct 2009, 3:57 p.m.


#33

Hi Luis,

I just cut the jumper, and it worked: Comma is now the radix, and period is now the thousands separator. I was pretty sure, since there is only one obvious jumper, but just wanted to be sure. Thanks.

BTW, I have tried to use an "E" suffix power board in a "C" suffix calc, and it does work, however, the contents of memory is lost when the ON/OFF switch is turned off, and you get a "pr error" display when it is turned back on. So I assume the "C" power board permits battery power to be fed to memory when the calc is switched off, but the "E" board does not.

Regards,

Michael


#34

This should not work actually, the ´E´ series power supply has no provision for the constant memory (power feed to the RAM IC when the calculator is OFF).

Cheers.

Luiz (Brazil)

Edited: 23 Oct 2009, 4:55 p.m.

#35

considering the HP 45 prototype I had already had the quartz as "custom addon" installed, one should consider this to be "common knowledge"

#36

Hi Geoff
When will the book be available? Please let me know if I can be helpfull in any way.

Best regards.

Johnny


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