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Non-working HP-67 question
07-02-2015, 03:15 PM (This post was last modified: 07-02-2015 03:18 PM by Ángel Martin.)
Post: #1
Non-working HP-67 question
Afraid my unit was victim of the infamous "charging-without-the-battery" fiasco - the LCD circuit is probably fried or out of order but I'm not really sure.

Are there easy ways to:

1. determine if that is the problem, and
2. get it fixed?

Thanks.
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07-02-2015, 03:58 PM
Post: #2
RE: Non-working HP-67 question
While the card reader circuitry (sense amplifier IC) can be damaged by connecting the charger to a HP-67 without a battery, the calculator itself will not be. Even for testing you should always have a good battery pack installed before connecting the charger. Do you have a good battery pack for it?

http://www.hpmuseum.org/cgi-sys/cgiwrap/...?read=9944
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07-03-2015, 02:54 PM (This post was last modified: 07-03-2015 02:56 PM by Ángel Martin.)
Post: #3
RE: Non-working HP-67 question
(07-02-2015 03:58 PM)Steve Simpkin Wrote:  While the card reader circuitry (sense amplifier IC) can be damaged by connecting the charger to a HP-67 without a battery, the calculator itself will not be. Even for testing you should always have a good battery pack installed before connecting the charger. Do you have a good battery pack for it?

http://www.hpmuseum.org/cgi-sys/cgiwrap/...?read=9944

Thank you for the pointer - right on target. My unit must have had something happened to it prior to me getting it. It's not reacting to any keystroke, the LCD is off and pretty much all is bricked. I tried it with a good battery from another unit (working) to no avail... unfortunately I also tried it without any battery pack on, so I probably made things worse Sad

Too bad there's no repair shop around the corner, would love to get that beauty on a functional state.

Çheers,
ÁM
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07-03-2015, 05:17 PM
Post: #4
RE: Non-working HP-67 question
(07-03-2015 02:54 PM)Ángel Martin Wrote:  Thank you for the pointer - right on target. My unit must have had something happened to it prior to me getting it. It's not reacting to any keystroke, the LCD is off and pretty much all is bricked. I tried it with a good battery from another unit (working) to no avail... unfortunately I also tried it without any battery pack on, so I probably made things worse Sad

Too bad there's no repair shop around the corner, would love to get that beauty on a functional state.

Çheers,
ÁM

Probably there is still a chance to repair your unit. Smile
You can unsolder an ACT chip from a working HP-25 or HP-21 and insert it in your HP-67. If that succeeds, you can order a "new ACT" for your HP-25 and you have two working units. If the card reader chip is defective this will not repair also your card reader unit. But it's just a try for you. I inserted an original HP-25 ACT in an HP-97 with success. The new ACT is not able to run a HP-67 or HP-97 directly.

Bernhard

That's one small step for a man - one giant leap for mankind.
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07-03-2015, 07:32 PM
Post: #5
RE: Non-working HP-67 question
(07-03-2015 05:17 PM)PANAMATIK Wrote:  order a "new ACT" for your HP-25

Where?

Thank you!
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07-03-2015, 08:12 PM
Post: #6
RE: Non-working HP-67 question
(07-03-2015 07:32 PM)anetzer Wrote:  
(07-03-2015 05:17 PM)PANAMATIK Wrote:  order a "new ACT" for your HP-25

Where?

Here ! Smile

http://www.panamatik.de/html/hp_calculat...r_kit.html

or PM to me

Bernhard

That's one small step for a man - one giant leap for mankind.
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07-04-2015, 06:58 AM
Post: #7
RE: Non-working HP-67 question
(07-03-2015 08:12 PM)PANAMATIK Wrote:  Here ! Smile

Oh! .-)

That sounds interesting indeed! I do not have one of the supported machines and would have to go out of the way to first find one...

Is an HP-67 ACT a realistic possibility?

I am not talking the near future, but just wonder if you are following that trail?

I guess there are quite a few machines out there to justify the effort, given the results you already have achieved...


Thank you
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07-04-2015, 07:24 AM
Post: #8
RE: Non-working HP-67 question
(07-04-2015 06:58 AM)anetzer Wrote:  Is an HP-67 ACT a realistic possibility?

I think, it is a realistic possibility, but not in the near future. The actual "new ACT" hardware does not support the HP-67/97, because it cannot read/write the DATA line in real time, which is necessary for communicating with the keyboard, card reader and printer (HP-97 only) chips. I would have to develop a new design and find another suitable processor, also there are unknown software details to explore about the card reader and printer.

I tried a "new ACT" in my HP-97 and it was able to run the display and executing the original ROM code.

Bernhard

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