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HP Forum Archive 19

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HP41 faster after crash and reset?
Message #1 Posted by Timo on 13 Mar 2010, 7:06 a.m.

I've had the first unpleasant experience with my Fullnut HP-41CV yesterday. During a business trip I got it out of its pouch for some quick calculations only to discover that it had turned completely nuts over night.

It did not turn on correct, displayed only garbage, etc. All quick recovery actions failed. When I got home I was able to reset it by taking out the batteries, shorting the contacts for half an hour (combined with pressing the On-key for two minutes), then pressing Backspace-Enter-On a couple of times. That when I was able to turn it on as normal again, and after performing a master clear (Backspace-On) the episode was over.

However, when I had my programs wanded in again I had the impression, that the calculator is now a good bit faster than before. Is that only in my imagination or can this really be true?

Maybe discharging all the capacitances in the system cleared some memory garbage or else??

And BTW, how can such a crash happen in the first place? I mean, I didn't even touch the unit before it went nuts...

Re: HP41 faster after crash and reset?
Message #2 Posted by Håkan Thörngren on 13 Mar 2010, 1:11 p.m.,
in response to message #1 by Timo

Maybe you just went out of USER mode? That can make the calculator a lot more responsive.

HP-41s can get lost, crash and lose the memory. It is not common, but I think it happens a little bit more often than most other LCD HP calculators which tend to be very stable. (I have extremely little experience with LED calculators, so I will not judge them).

I do not know why, maybe it is due to the zebra strip in the early ones, in combination with temperature variations?

Re: HP41 faster after crash and reset?
Message #3 Posted by Timo on 15 Mar 2010, 1:40 p.m.,
in response to message #2 by Håkan Thörngren

Oh man, sorry for this late response, but I do not find lots of time for this forum at the moment...

I don't think its attributed to the USER-Mode since I exit this mode everytime I do not need it. I don't know, maybe I was just so happy to see my little friend back alive, that I thought it's also slightly faster now...

However, what I did find regarding possible causes of a crash is this PDF: See this...

It seems to be a letter from HP to a customer who sent his HP 41 to HP for repair. In this letter they mention that strong magnetic fields or electromagnetic discharges can cause such problems on a HP-41. I did actually hear the high pitched noise that depressed keys can emit as mentioned in this document, though it was hardly discernable.

I don't know, maybe I had it stored to close to this age-old TV-Set in my hotel room... ;)

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