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illcendiary · 12-21-2016, 12:02 AM

Hello all,

I was going through some old belongings in storage recently and came across my old, battle-tested HP 32SII calculator from high school and college. I had relegated the calculator to storage after thinking it was dead. I decided to try and revive it yesterday and realized that the calculator just needed a new set of batteries and a hard reset.

The calculator had still has some issues with button responsiveness and LCD screen readout. I have been able to regain button functionality by replacing the old foam underneath the keyboard ribbon with a few strips of mouse pad foam, but I am still having trouble with the LCD readout. As you can see in the attachments, some of the LCD "boxes" that make up the digits/characters don't light up when activated.

You can also tell from the picture of the screen with the contrast turned all the way up that those "boxes" are still somehow turned off, which indicates to me that they're either broken, or I perhaps have some faulty connections on the interior.

Has anyone come across an issue like this, and if so, what's a potential fix? Thanks all for the assistance.

PANAMATIK · 12-21-2016, 06:38 AM

(12-21-2016 12:02 AM)illcendiary Wrote: You can also tell from the picture of the screen with the contrast turned all the way up that those "boxes" are still somehow turned off, which indicates to me that they're either broken, or I perhaps have some faulty connections on the interior.

Has anyone come across an issue like this, and if so, what's a potential fix? Thanks all for the assistance.

I had this issue with an HP-22S. It is typical for not having enough pressure at the LCD contact areas. Separate the PCB from the LCD display, clean the contact areas with 50% isopropylalcohol and reattach the PCB. When fixing with the metal clips, turn them enough to get the boards pressed together properly.

see: https://www.youtube.com/watch?v=Uo4EZG0NQbc

Bernhard

Thomas Radtke · 12-21-2016, 11:51 AM

Thanks for sharing your video! Didn't knew something like this existed :-).

**Katie Wasserman** · 12-21-2016, 03:57 PM

(12-21-2016 11:51 AM)Thomas Radtke Wrote: Thanks for sharing your video! Didn't knew something like this existed :-).

Me neither. I like that this person is able to operate on his 32sii with such crude and rusty tools. It makes me feel somewhat ashamed of all the fancy, expensive tools I use to work on my calculators.

Logan · 12-21-2016, 04:27 PM

(12-21-2016 03:57 PM)Katie Wasserman Wrote: Me neither. I like that this person is able to operate on his 32sii with such crude and rusty tools. It makes me feel somewhat ashamed of all the fancy, expensive tools I use to work on my calculators.

Ha, so it's my video and this made me laugh. I'd love to see more calculator repair videos by people with more experience such as yourself.

But in the meantime, if I attempt any more repairs, you'll have to see those crude, rusty tools again Big Grin

jebem · 12-21-2016, 06:19 PM

(12-21-2016 04:27 PM)Logan Wrote: But in the meantime, if I attempt any more repairs, you'll have to see those crude, rusty tools again

Thank you, Logan!
Nice repair jobs, specially on the HP-20S where we can see all the procedure from start to end.
Clean, precise jobs. Really enjoyed to watch them.
One image is worth one thousand words,they say: It shows how hard these HP cases can be pushed without breaking. This is very useful for anyone trying a repair on these machine models.

I remember to read elsewhere that a nail cutter makes wonders when it comes to convince these HP machines to give up and let us enter to do a maintenance job.

Concerning the rusty tools, I love them. I have plenty of them from my teenager days and somehow I can't get rid of them as they have been serving me for so many years. In fact I have a couple of rusty pliers that I keep using because they are so handy and precise, and I can't find a good replacement for them (well, I don't even try to).

illcendiary · 12-21-2016, 06:52 PM

Thanks all for the help! Unfortunately I have some bad news. I suppose I had twisted the PCB ties one too many times, and one of them snapped on me. In addition, the metal contact that contacts that battery/PCB also snapped off. I suppose it was just time for this one to go. Chalking this up as a learning experience for the future.