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HP 32SII success and woes
02-10-2015, 03:59 AM (This post was last modified: 02-10-2015 04:20 AM by Sanjeev Visvanatha.)
Post: #1
HP 32SII success and woes
I acquired an almost new looking 32SII today. That is where my celebrating stops.

It did not have batteries, but I was assured that the self test passed.

I put in new batteries when I got home and powered it up. It says "memory clear", and after dismissing the message with ON key, I get what appears to be some gibberish on the screen:

   

The keyboard is unresponsive, the shift annunciators flash when the corresponding shift key is pressed. Funnily, the self test described in the Owner's Manual passes, and ends with "32SII - OK".

There is no way to turn off the calculator, since it does not respond to the OFF command from the keyboard.

I had a closer look at the battery compartment, and there is one funny little thing going on there. On one of my other Pioneers, there is a small metallic plate covering the top centre PCB twist clip. On this 32SII, that plate is missing. I am not sure what its function is on my other Pioneer. See photos showing the difference.

       

Does the gibberish on the screen mean anything to anybody? I could not see it as part of the error codes in the manual. Also, I cannot see any indications that the unit was opened up in the past.

Is this fixable, or is it a parts machine now? Thank you for any insight!

-- Sanjeev Visvanatha
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02-10-2015, 05:20 AM
Post: #2
RE: HP 32SII success and woes
(02-10-2015 03:59 AM)Sanjeev Visvanatha Wrote:  Is this fixable, or is it a parts machine now? Thank you for any insight!

Try the solutions on this page.


Cheers,
marcus

Kind regards,
marcus
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02-10-2015, 07:34 AM (This post was last modified: 02-10-2015 07:37 AM by Geoff Quickfall.)
Post: #3
RE: HP 32SII success and woes
Hello Sanjeev

Turn off the calc.

Now press down gently on the top of the metal bezel just below the screen window.

While maintaining the pressure on the bezel just under the screen turn the calc on.

Continuing to press on the bezel, test the calc with the self tests and keyboard and report back.

The twisty thing is a twist clamp that locks the PCA in position. It also serves to press the PCA contact points into the foam wich supports the keyboard contact ribbon. There are six of these twistees. I just repaired a 32SI with compressed foam pressure pad. These pads harden and deform over time and cause the keyboard contact ribbon to lose connectivity with the PCA. This has the effect of causing rows of keys to malfunction.

The twistees also hold the lcd panel in firm contact with the zebra strips and PCA. The garbage display could be that a twistee has failed (missing in your photo) and there is a failure at the LCD-zebra strip-PCA interface.

The only solution is to open it up.

Check out these URLs:

Click on calculator restorations:

http://h20331.www2.hp.com/hpsub/download...e_2010.pdf

And 32sii self tests:

http://www.rskey.org/~mwsebastian/selfte...tm#pioneer

So in conclusion, a missing twistee at your photos location would effect the top zebra strip contact for the LCD to PCA contact. Any others at the mid section would effect the key responses. The compressed foam pressure pad would exacerbate the problem at the keyboard to PCA interface.

If the twistee is missing it would appear someone has been in the calc. You only get a few attempts at repairs as these twistees will fatigue and break. The way they are designed they exude a large compression force and are under stress. Untwisting and re twisting numerous times will result in broken twistees.

Fingers crossed, geoff
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02-10-2015, 01:56 PM
Post: #4
RE: HP 32SII success and woes
Hello Sanjeev,

the photo showing the display of your calculator after you "put in new batteries", reminds me of a similar (but most probably totally different) gibberish which appeared on one of my 32sII right after battery replacement. Shorting the calculator did not resolve the problem. So I replaced the new batteries again, by used ones from another model: It worked...

As far as I remember, the new batteries used in first place had a slightly higher voltage than specified for standard LR44. A possible explanation to the observed malfunction.

So, before opening the calculator for a lengthy repair, you might give this procedure a try.

Good luck!
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02-10-2015, 11:53 PM
Post: #5
RE: HP 32SII success and woes
(02-10-2015 05:20 AM)MarkHaysHarris777 Wrote:  Try the solutions on this page.

Thank you. This is what I had tried at first. No joy.

-- Sanjeev Visvanatha
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02-10-2015, 11:55 PM
Post: #6
RE: HP 32SII success and woes
(02-10-2015 01:56 PM)renif Wrote:  Hello Sanjeev,

the photo showing the display of your calculator after you "put in new batteries", reminds me of a similar (but most probably totally different) gibberish which appeared on one of my 32sII right after battery replacement. Shorting the calculator did not resolve the problem. So I replaced the new batteries again, by used ones from another model: It worked...

As far as I remember, the new batteries used in first place had a slightly higher voltage than specified for standard LR44. A possible explanation to the observed malfunction.

So, before opening the calculator for a lengthy repair, you might give this procedure a try.

Good luck!

Hello renif,

I tried several new battery combinations, and even the ones that work in my 22S and 42S. This did not change outcomes.

-- Sanjeev Visvanatha
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02-11-2015, 12:13 AM
Post: #7
RE: HP 32SII success and woes
Geoff,

Thank you for your reply. I did as suggested and applied light pressure to the top of the bezel below the LCD and performed the self test. It passes the self test, but does display further gibberish once the self test is exited.

In the battery compartment I can see the top centre twisty clip and it appears as it should. What is missing is a metal plate that goes between it and the tab on the battery cover. This is in comparison to both my 42S and 22S. I do not know if this metal plate serves another purpose.

I also had the calculator performing normally for a while today, but could not replicate the conditions leading to this.

I will study the article you referenced when I can get to my laptop today.

-- Sanjeev Visvanatha
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02-11-2015, 04:15 AM
Post: #8
RE: HP 32SII success and woes
(02-11-2015 12:13 AM)Sanjeev Visvanatha Wrote:  What is missing is a metal plate that goes between it and the tab on the battery cover. This is in comparison to both my 42S and 22S. I do not know if this metal plate serves another purpose.

Is it possible that the metal plate in the battery compartment serves as a ground for the PCB? It looks like the metal plate makes contact with the twist clip on my other Pioneer.

[Image: attachment.php?aid=1604]

-- Sanjeev Visvanatha
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02-11-2015, 02:12 PM
Post: #9
RE: HP 32SII success and woes
(02-11-2015 04:15 AM)Sanjeev Visvanatha Wrote:  Is it possible that the metal plate in the battery compartment serves as a ground for the PCB? It looks like the metal plate makes contact with the twist clip on my other Pioneer.

FYI - I have a Pioneer handy (10B from 98) that has no metal plate in this location and it works fine; doesn't really prove anything, just a nother data point. I'm sure there were several h/w design improvements over tha many years Pioneers were produced.

--Bob Prosperi
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02-11-2015, 02:55 PM (This post was last modified: 02-11-2015 02:56 PM by Don Shepherd.)
Post: #10
RE: HP 32SII success and woes
I've got three 17b's, all have the metal plate and work fine. I've got one 32sii, it does not have the metal plate and it has always worked fine as well. My guess is the lack of the metal plate is probably not to blame for this particular problem.
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02-11-2015, 03:37 PM (This post was last modified: 02-11-2015 04:20 PM by ElectroDuende.)
Post: #11
RE: HP 32SII success and woes
(02-11-2015 02:55 PM)Don Shepherd Wrote:  I've got three 17b's, all have the metal plate and work fine. I've got one 32sii, it does not have the metal plate and it has always worked fine as well. My guess is the lack of the metal plate is probably not to blame for this particular problem.

Neither my 32SII, 20S nor 21S have the plate, while the 17BII and 27S have it. I'll have to check on the 22S, but its out of reach now... As you say, it shouldn't matter if it is present or not regarding this problem.

I once saw this very same bahaviour in a 32SII (with different symbols on display), after a change of batteries, but it was solved just shorting the terminals with a coin and pressing ON several times. After refitting batteries everything worked again.

As it doesn't seem this is your case, next step will imply opening the case and looking for bad connections (display zebra connectors) or even soldering defects in the main (and only) integrated circuit. It is not the tape automated bonding circuit of the first pioneer models, but it is still quite sensitive, as it is placed in a hole inside the PCB:

http://www.keesvandersanden.nl/calculato...repair.php
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02-11-2015, 03:55 PM
Post: #12
RE: HP 32SII success and woes
The metal plate is grounded but only really matters if the unit has a buzzer and only when the buzzer has only one spring contact.

As for the gibberish on the screen, if there is a key or combination of keys that could cause this (a big if and I don't know the answer) then there could be a short in the keypad matrix. I see this all the time. If it is so it is possible to dismantle the keypad and clean the matrix. (I did one yesterday.) This is not easy though.

Whatever you do don't throw the calculator away!

Lead, Follow or Get Out of the Way...
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02-11-2015, 10:55 PM
Post: #13
RE: HP 32SII success and woes
(02-11-2015 02:55 PM)Don Shepherd Wrote:  I've got three 17b's, all have the metal plate and work fine. I've got one 32sii, it does not have the metal plate

(02-11-2015 03:37 PM)ElectroDuende Wrote:  Neither my 32SII, 20S nor 21S have the plate, while the 17BII and 27S have it. I'll have to check on the 22S, but its out of reach now... As you say, it shouldn't matter if it is present or not regarding this problem.

I just checked 2 32SII's, both from '98 - no plate, and a 32S from '90 and it does have the plate.

This small sampling seems to imply the early Pioneers did have the metal plate, while late model Pioneers did not have the metal plate.

As noted above, this is likely not related to the problem, but it does contribute one more useless little factoid about the differences within the Pioneer family.

--Bob Prosperi
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02-11-2015, 11:32 PM
Post: #14
RE: HP 32SII success and woes
(02-11-2015 02:12 PM)rprosperi Wrote:  FYI - I have a Pioneer handy (10B from 98) that has no metal plate in this location and it works fine; doesn't really prove anything, just a nother data point. I'm sure there were several h/w design improvements over tha many years Pioneers were produced.

Thanks for checking Bob.

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02-11-2015, 11:33 PM
Post: #15
RE: HP 32SII success and woes
(02-11-2015 02:55 PM)Don Shepherd Wrote:  I've got three 17b's, all have the metal plate and work fine. I've got one 32sii, it does not have the metal plate and it has always worked fine as well. My guess is the lack of the metal plate is probably not to blame for this particular problem.

Don - Thank you for the reply. As Rob pointed out, there could be several production variants of the Pioneer case.

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02-11-2015, 11:36 PM
Post: #16
RE: HP 32SII success and woes
(02-11-2015 03:37 PM)ElectroDuende Wrote:  Neither my 32SII, 20S nor 21S have the plate, while the 17BII and 27S have it. I'll have to check on the 22S, but its out of reach now... As you say, it shouldn't matter if it is present or not regarding this problem.

I once saw this very same bahaviour in a 32SII (with different symbols on display), after a change of batteries, but it was solved just shorting the terminals with a coin and pressing ON several times. After refitting batteries everything worked again.

As it doesn't seem this is your case, next step will imply opening the case and looking for bad connections (display zebra connectors) or even soldering defects in the main (and only) integrated circuit. It is not the tape automated bonding circuit of the first pioneer models, but it is still quite sensitive, as it is placed in a hole inside the PCB:

http://www.keesvandersanden.nl/calculato...repair.php

I have used name brand new batteries, both Alkaline and Silver Oxide. I get the same results.

In the link you provided, it looks as though that 32SII has the metal plate. But it is hard to tell for sure.

I may have to open her up...

-- Sanjeev Visvanatha
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02-11-2015, 11:42 PM
Post: #17
RE: HP 32SII success and woes
(02-11-2015 03:55 PM)Bruce Larrabee Wrote:  The metal plate is grounded but only really matters if the unit has a buzzer and only when the buzzer has only one spring contact.

As for the gibberish on the screen, if there is a key or combination of keys that could cause this (a big if and I don't know the answer) then there could be a short in the keypad matrix. I see this all the time. If it is so it is possible to dismantle the keypad and clean the matrix. (I did one yesterday.) This is not easy though.

Whatever you do don't throw the calculator away!

Hmmmmm - so I connected the central top Twisty clip holding the PCB in place to the negative battery terminal (assuming this is equivalent to ground - I am not an EE). Voila, the unit operates normally, but shows the low battery indicator.

This leads me to speculate that there is a grounding issue on the PCB. That metal plate also serves to protect eyes/objects from touching the PCB and the integrated circuit. It is possible the previous owner was not careful in this regard.

So, it looks like I am opening it up. I may try my hand opening a 10B first (no offense to anyone here), before working on this unit.

Any thoughts on the grounding issue are welcome.

Thank you all for your input and time.

-- Sanjeev Visvanatha
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02-11-2015, 11:50 PM (This post was last modified: 02-11-2015 11:50 PM by ElectroDuende.)
Post: #18
RE: HP 32SII success and woes
(02-11-2015 10:55 PM)rprosperi Wrote:  I just checked 2 32SII's, both from '98 - no plate, and a 32S from '90 and it does have the plate.

This small sampling seems to imply the early Pioneers did have the metal plate, while late model Pioneers did not have the metal plate.

As noted above, this is likely not related to the problem, but it does contribute one more useless little factoid about the differences within the Pioneer family.

Later in manufacturing or in design?

My units:

17BII - 1996 - has metal plate
20S - 1991 - doesn't have plate
21S - 1991 - doesn't have plate
22S - 1990 - has metal plate
27S - 1988 - has metal plate
32SII -1993 - doesn't have plate

In the begining I thought it was used only in the "high end" hardware (dot matrix, buzzer) but finding it in the 22S and not in the 32SII throws this...

So it is possible that, as you say, it was used in first units designed and removed later, but 20S and 21S are quite early models...
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02-12-2015, 12:21 AM
Post: #19
RE: HP 32SII success and woes
(02-11-2015 11:50 PM)ElectroDuende Wrote:  
(02-11-2015 10:55 PM)rprosperi Wrote:  I just checked 2 32SII's, both from '98 - no plate, and a 32S from '90 and it does have the plate.

This small sampling seems to imply the early Pioneers did have the metal plate, while late model Pioneers did not have the metal plate.

As noted above, this is likely not related to the problem, but it does contribute one more useless little factoid about the differences within the Pioneer family.

Later in manufacturing or in design?

My units:

17BII - 1996 - has metal plate
20S - 1991 - doesn't have plate
21S - 1991 - doesn't have plate
22S - 1990 - has metal plate
27S - 1988 - has metal plate
32SII -1993 - doesn't have plate

In the begining I thought it was used only in the "high end" hardware (dot matrix, buzzer) but finding it in the 22S and not in the 32SII throws this...

So it is possible that, as you say, it was used in first units designed and removed later, but 20S and 21S are quite early models...

Actually the 20S and 21S are relatively late Pioneer models, arriving in Jan '89 with the 10B; only the 17BII and 32SII came later.

The 17BII seems to break the idea that later models dropped the metal bar; I just checked 2 17BIIs, a brown and a black version; both have the bar. Could be ralted to IR, but the 22S had no IR. Hmmm...

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02-13-2015, 03:07 AM
Post: #20
RE: HP 32SII success and woes
I tried my hand at opening a 10B before attempting opening the 32SII. The Indonesia built 10B was easier to open than the Singapore built Scientific.

In any case, all 6 twist clips are intact.

   

The problem persists.

-- Sanjeev Visvanatha
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