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HP-25E GPS ACT Version
06-25-2017, 06:05 PM
Post: #1
HP-25E GPS ACT Version
Hello all,

I am considering purchasing an HP-25E GPS ACT Version kit from Panamatik.

I do not currently have my own HP-25, but I found this one on TAS:

http://www.ebay.com/itm/HP-25-ULTRA-RARE...SwCkZZSgMx

Can anyone offer me some advice on whether or not this particular HP-25 might be a good candidate for performing this upgrade? No strings attached. I am looking for your advice, and I understand that I make my own decisions, and the results of those decisions are on me. Please let me know what you thought / concern / advice is.

Also, I guess I have another question: Would I simply have to purchase the HP-25E GPS ACT Version kit, or would I first have to purchase the HP-25E Extended ACT Version and then add the HP-25E GPS ACT Version on top of that?

Thanks, in advance, for any assistance you may have to offer.

smp
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06-25-2017, 10:05 PM
Post: #2
RE: HP-25E GPS ACT Version
(06-25-2017 06:05 PM)smp Wrote:  Can anyone offer me some advice on whether or not this particular HP-25 might be a good candidate for performing this upgrade?
...
Also, I guess I have another question: Would I simply have to purchase the HP-25E GPS ACT Version kit, or would I first have to purchase the HP-25E Extended ACT Version and then add the HP-25E GPS ACT Version on top of that?

It's very hard to say from the seller's vague description; leaking batteries may have damaged components and traces inside, there is no way to tell without opening the case and inspecting.

Ask the seller what "not working' means; i.e. does LED come on at all? Do keys all click and feel OK, even if not working properly, etc.

That said, it appears to be in good overall condition, seller has 100% rating after > 1000 FB, so can probably be trusted to do the right thing if it turns bad. I'd say it's an acceptable risk, the price is pretty good.

I believe the GPS kit is the only item to purchase, it says "Each kit contains the ACT extended version, the GPS module and a step up converter to supply the module." Bernhard can clarify to be 100% sure.

--Bob Prosperi
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06-25-2017, 11:50 PM
Post: #3
RE: HP-25E GPS ACT Version
Hi Rob,

Thank you very much for all your attention and advice.

(06-25-2017 10:05 PM)rprosperi Wrote:  It's very hard to say from the seller's vague description; leaking batteries may have damaged components and traces inside, there is no way to tell without opening the case and inspecting.

Yes, I get it. That's pretty much what I expected to hear.

(06-25-2017 10:05 PM)rprosperi Wrote:  Ask the seller what "not working' means; i.e. does LED come on at all? Do keys all click and feel OK, even if not working properly, etc.

Thanks very much for the hints about what to ask for!

(06-25-2017 10:05 PM)rprosperi Wrote:  I believe the GPS kit is the only item to purchase, it says "Each kit contains the ACT extended version, the GPS module and a step up converter to supply the module." Bernhard can clarify to be 100% sure.

Yes, again. Right after I posted my questions, I finally read that statement down at the bottom of the description. Thanks very much for pointing it out.

I think I'm going to pass on this particular project. A bit too risky for me right now. I saw some postings over on the Vintage Computer Forum about a fellow who just acquired a nice pile of HP 86 equipment and documentation. He inspired me to pull my HP 86B out of storage and get it set up again. So now I'm actively playing with both my HP 71B and my HP 86B.

smp
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06-26-2017, 07:19 AM
Post: #4
RE: HP-25E GPS ACT Version
(06-25-2017 10:05 PM)rprosperi Wrote:  Bernhard can clarify to be 100% sure.

You clarified this already.

What is the worst case when buying a "not working" HP-25, what cannot be seen from outside?

1.) Display defective, segments are missing.
If the display has missing segments, there is no way of repair. Only the new Woodstock LED module could be installed, but it has smaller digits and a different look.

2.) Keyboard buttons non responding due to corrosion.
Even very corroded keyboards can be brought back to good responding within one day by using DeOxit red and a small steel wire to clean the contact area inside the pores below the buttons.

3.) Electrical fault by corroded wires or defective components.
Provided you are equipped with tools to replace components, all electrical damage inside the calculator can be repaired. Corroded traces could be easily repaired. Switching power supply can be easily repaired by replacing the 2 transistors and zener diode (less than half €). The ACT can be replaced (80,- €). The most difficult repair would be to replace also defective display drivers.

In every case when buying the new ACT, I would offer you to send the complete calculator for a guaranteed repair.

Bernhard

That's one small step for a man - one giant leap for mankind.
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