Repairing/Restoring 48SX

[rprosperi]

(10-27-2018 09:54 PM)brickviking Wrote:  Incidentally, what's in the 2.16 ROM? I can't extract it, nor install it on my 50G (because I can't extract it).

The 50g v2.16 ROM is for the PC-based Emulator from HP, it will not work in a h/w 50g, but they are essentially the same functionality.

[Craig Bladow]

(10-27-2018 08:22 PM)EugeneNine Wrote:  

(10-27-2018 07:01 PM)Craig Bladow Wrote:  How do you keep it together after the 10 pins have been drilled out?

some small push pins or screws. They make pins that have knurling to prevent them from backing out, but ideally I want to find small screws so they can be taken apart again.

Please post the solution that worked for you when you are done.

[brickviking]

(Apologies for the offtopic post)

(10-27-2018 11:12 PM)rprosperi Wrote:  

(10-27-2018 09:54 PM)brickviking Wrote:  Incidentally, what's in the 2.16 ROM? I can't extract it, nor install it on my 50G (because I can't extract it).

The 50g v2.16 ROM is for the PC-based Emulator from HP, it will not work in a h/w 50g, but they are essentially the same functionality.

Hm, except the ability to copy anything into Port 2 or access an SD, real or emulated. Sigh. If they'd added that, it would have been a very good comparison for x49gp. As it is, there's 671k going begging. Why oh why did HP put what amounts to a somewhat neutered HP calculator out as an emulator?
[/offtopic]

(Post 311)

[rprosperi]

(10-28-2018 02:22 AM)brickviking Wrote:  Hm, except the ability to copy anything into Port 2 or access an SD, real or emulated. Sigh. If they'd added that, it would have been a very good comparison for x49gp. As it is, there's 671k going begging. Why oh why did HP put what amounts to a somewhat neutered HP calculator out as an emulator?
[/offtopic]

Just guessing here, but maybe to entice folks that want to use full features to actually buy a calculator?

[brickviking]

Problem is, the HP-50G isn't sold by HP any more, so that contention is out the window. In addition, the average price has shot up considerably since the $83 I paid for a new unit plus the $34 I paid just to get it to me. The minimum prices I can find on Amazon start from $95, second hand! and work their way up through $289 (all prices quoted in USD).

In the interests of getting my information correct, I decided to see what HP was selling them for, only problem is, they're not selling calculators through hp.com, unless they're selling it through some subsidiary, so I lucked out there.

(Post 312)

[Thomas Okken]

There are plenty of reasonably priced 50g's for sale on eBay, though. I got one there earlier this year, not in mint condition but working perfectly, for $50 including shipping from Venezuela to the U.S. There are at least eight on offer for less than $100 at the moment, all claimed to be working, the cheapest for $34.

[EugeneNine]

Is there a trick to getting the LCD lined up right or is it just trial and error?

[mfleming]

Hi Eugene,

I take it you have already removed the black LCD from a donor. If so, was it a 39G and how did you open it? I haven't been able to find a teardown description for the calculator and I see no screws in the battery compartment or under the feet.

Any pointers by anyone would be appreciated. I already have a 48SX I opened a while back for repair, and would really like to see a better display!

~Mark

[EugeneNine]

I haven't gotten a 39g yet, was re-assembling a couple of the 48sx's to test the foam tape I got to press the keyboard cable onto the pcb.

[EugeneNine]

I found its just tricky to get everything lined up and pressed together tight enough

[Sanjeev Visvanatha]

My 48sx keyboard needs replacing as the Enter key is physically broken, and ON does not register at all even if I press the bezel in the correct place.

So, I am looking at replacing the keyboard and swapping LCD for the black version. Some questions:

1. If I get a 48S, is the keyboard going to work with the PCB from my 48SX?
2. Are there any opening instructions for a 39GS? I have ordered one, but I am not sure how the unit opens up.

[mfleming]

Have a look at this post, supplied by Massimo, to a similar query on my part for opening a 49g. Although I meant a 39g like yours, the mechanical assembly of the two calculators is the same. I used the instructions to put a 39g black LCD into my own 48sx.

http://www.hpmuseum.org/cgi-sys/cgiwrap/...read=42503

As to your first question on replacing the 48sx keyboard, the keyboard assembly is held in place by a number of heat stakes. That would be an unenviable task to clip them, transfer the keys and layers, then remelt the stakes. There's a better chance you can just swap out the whole faceplate, giving you a 48s front with a 48sx interior. I picked up a 50g frankencalc with a 49g+ face a while back on TAS, so it probably can be done.

~Mark

[acoto]

Watch out on display donors. Just discovered 5 minutes ago, on the hard way not all 39GS displays are compatible with the 48S/SX/G/GX.

The display on the sacrificed 39GS uses horizontal+vertical lines of contacts instead of top+bottom on the 48G+ I am working on.

Serial Number of incompatible display 39GS: CNA 92403005

[Sanjeev Visvanatha]

(02-11-2019 04:20 PM)mfleming Wrote:  Have a look at this post, supplied by Massimo, to a similar query on my part for opening a 49g. Although I meant a 39g like yours, the mechanical assembly of the two calculators is the same. I used the instructions to put a 39g black LCD into my own 48sx.

http://www.hpmuseum.org/cgi-sys/cgiwrap/...read=42503

As to your first question on replacing the 48sx keyboard, the keyboard assembly is held in place by a number of heat stakes. That would be an unenviable task to clip them, transfer the keys and layers, then remelt the stakes. There's a better chance you can just swap out the whole faceplate, giving you a 48s front with a 48sx interior. I picked up a 50g frankencalc with a 49g+ face a while back on TAS, so it probably can be done.

~Mark

Thank you for the instructions link. I’m still waiting for the donor unit.

I think I meant swapping out the entire upper half of a 48s, and swapping metal overlays also. So I was wondering if upper half from a 48s is compatible with the 48sx PCB. I assume it is.

[Sanjeev Visvanatha]

(02-11-2019 09:44 PM)acoto Wrote:  Watch out on display donors. Just discovered 5 minutes ago, on the hard way not all 39GS displays are compatible with the 48S/SX/G/GX.

The display on the sacrificed 39GS uses horizontal+vertical lines of contacts instead of top+bottom on the 48G+ I am working on.

Serial Number of incompatible display 39GS: CNA 92403005

Oh this is good to know ! I hope the one I have ordered is compatible !

[Han]

I definitely recommend a black-pixel screen if you can find one that works.

https://users.ju.edu/hduong/repair/

[Paul Berger (Canada)]

(02-11-2019 09:44 PM)acoto Wrote:  Watch out on display donors. Just discovered 5 minutes ago, on the hard way not all 39GS displays are compatible with the 48S/SX/G/GX.

The display on the sacrificed 39GS uses horizontal+vertical lines of contacts instead of top+bottom on the 48G+ I am working on.

Serial Number of incompatible display 39GS: CNA 92403005

The display in the 39GS is completely different what you want for a donor is a 39G or even a 49G. All the models that followed use a different display with a different connection technology.

Paul.

[rprosperi]

(02-14-2019 01:51 AM)Paul Berger (Canada) Wrote:  The display in the 39GS is completely different what you want for a donor is a 39G or even a 49G. All the models that followed use a different display with a different connection technology.

Sorry, I gave bad advice (far) above, suggesting all of the 39G variants as possible donors for adding black LCD to a 48SX.

Paul - do you know if the 39G+ is compatible? It's neither the same h/w as the 39g/40g or the 39gs/40gs, so it's not obvious which style (old or new) LCD it has. These are not too common, but are typically quite cheap as well.

[Eric Rechlin]

(02-14-2019 02:08 AM)rprosperi Wrote:  Paul - do you know if the 39G+ is compatible? It's neither the same h/w as the 39g/40g or the 39gs/40gs, so it's not obvious which style (old or new) LCD it has. These are not too common, but are typically quite cheap as well.

The 39g+ is in the same series as the 39gs/40gs/48gII/49g+/50g and therefore its screen is incompatible with the older calculators.

He needs a screen from a Saturn calculator, not an ARM calculator. That means 38G, 39G, 40G, 48G/G+/GX/S/SX, or 49G.

[rprosperi]

(02-14-2019 02:41 AM)Eric Rechlin Wrote:  The 39g+ is in the same series as the 39gs/40gs/48gII/49g+/50g and therefore its screen is incompatible with the older calculators.

He needs a screen from a Saturn calculator, not an ARM calculator. That means 38G, 39G, 40G, 48G/G+/GX/S/SX, or 49G.

Thanks Eric, I had no idea the 39g+ was ARM-based. What an uninspired, and ugly, initial Algebraic ARM machine...