Short Battery Life on my HP-41CX

[Paul Schreck]

My trusty HP-41CX eats batteries like there's no tomorrow! It's been perhaps 20 years or so since it's been used regularly (when I was last in college). However, whenever I need it again and install new N-size batteries, I find it dead when I need it again in a few days or weeks. It's sure not being used heavily when it's on, and I'm always careful to turn it off. I remember the batteries having a somewhat short lifespan (months) in college, but now something seems wrong. My eighth grader is prepping for SATs and I hope to pass down my trusty -41CX.

Any suggestions for this battery problem?

[Ron Ross]

Since its a CX, do you have any alarms or other background programs running. Perhaps you have a module or other accessory that is also gobbleing up juice while you think it is off.

It could also be something on the inside across some contacts that might be corrected by a good cleaning.

Now, about loaning it to your younger one. Don't. Buy an Hp33s for them instead. It is actually a bit tougher and is easily replacable (and fairly cheap at $50 retail, Walmart). Later you can give them the Hp41Cx after you see how well they treat a $50 calculator.

And it is a dual mode calculator ie both RPN and algebraic.

Another calculator to consider is a graphics such as the Hp48Gii (although it is very complex and everyone in school will be using the Ti-83/84). It is also a dual mode calculator, although as an algebraic, it sucks compared to a Ti-86 which it compares most with (although it has a CAS, which may become a crutch to a younger ueser).

I wouldn't bother to loan an older Hp to your eigth grader and I say this after some experience (old piece of CRAP, why didn't Dad get me something new?!).

[Paul Schreck]

Thanks for the advice; I was checking out the latest versions on hpshopping.com and was considering the -33c. It may be too early to hand him a graphing device. I think those things are not authorized during SAT/ACT as well, but I'm not sure of the current policy but I will be soon!

I've always suspected the clock as the culprit because I've never used any peripherals with my -41CX. The fanciest I ever got were basic engineering equations to save time & keystokes during exams. Is there any way to disable the clock? It's not discussed in the manuals anywhere that I could ever find.

[Wayne Brown]

Quote:

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It may be too early to hand him a graphing device. I think those things are not
authorized during SAT/ACT as well, but I'm not sure of the current policy but I will be soon!

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I don't know the current policy, but my son was allowed to use his 48GX on the ACT a few years ago. He had to cover the IR port with tape (to eliminate the possibility of communicating with others during the test), but there was no objection to the calculator itself. They didn't even make him clear the memory or remove his RAM and ROM cards.

[John Smitherman]

Quote:

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Thanks for the advice; I was checking out the latest versions on hpshopping.com and was considering the -33c. It may be too early to hand him a graphing device. I think those things are not authorized during SAT/ACT as well, but I'm not sure of the current policy but I will be soon!

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Another reason for buying the 33s versus other scientific calculators is the quality of documentation available for the 33s. The 33s comes with a good manual plus there are a set of learning modules available for the 33s on HP's web site. Most other scientific calculators come with brief and sometimes poorly written instructions printed on a single sheet of paper.

Good luck!

John

[David Smith]

It may be the electrolytic capacitors in the power supply are leaky and neeed to be replaced.

[Paul Schreck]

Thanks for the reply. Would you have any suggestions for:

1. Troubleshooting techniques to isolate the problem, or
2. Perhaps somewhere I could send it for diagnostics or repair.

[Joe Edwards]

I have sent a couple of calcs to fixthatcalc.com with good results. He is a bit slow, but that is due to a backlog of work - it is a hobby, not a full time business. But, if you aren't in a hurry, he might be able to help you out.

If I am not supposed to post websites here, feel free to delete my post.

Joe