HP41.org

My trusty 41c started freezing up a couple of weeks ago. I figured that after 30 years it was due for pasture, so I put it away and bought a CX on ebay. It turned on once, then the display went blank. After a week of trying to coax a number onto the display I sent it back. I just bought a CV and it's doing the same thing (blanking out). Having a 2nd one also lose its display has made me wonder if it's an environmental factor. It's the same location that has worked for years, so I don't think the problem is ambient electrical fields. What else could cause 3 calculators w/ good batteries to stop displaying?

Are you 100% sure that your batteries are good? Did you put an application module in all of them? Did you use the same battery holder (or rechargeable pack)?

Yes, I'm sure that the batteries are good. I have a 2nd 41C and it works fine with the same batteries (which, incidentally, were purchased 8 days ago in a sealed package).

I never heard anything about environmental factors causing that. I have used a HP-41CX in many environments, ranging from cold to hot, from dry to humid (up to 95%). Also, I haven't heard of any problems that other users had.
This won't help you, but these problems are uncommon for the HP-41C series.

Well, now I'm just thinking about the coconut-series that has rectangular display edges. This series is a bit more sensitive to mechanical stresses, since the connection between the PCB and keyboard/display depend on pressure. But they don't fail simply because of transportation, mostly it is because the previous owner has opened the case and cracked the plastic posts.

I used to be a surveyor, and numerous times I encountered problems with the display blanking out when working under high-power transmission lines (mostly 230KVA). A number of other people have encountered this difficulty too, so it appears to be endemic to the 41 displays. After about a half-day away from the force fields the display returns. This is not what happened with the ones I just tried - one displayed once, then stopped; the other one comes on for 1/2 second and then goes blank. I sent both back, but would be interested in a solution that I could pass back to them.

Predecessor problem:
My original 41C (the old "coconut" as you call it) works fine for a while, but then freezes up with the number displayed at time of freeze-up. This happens randomly - sometimes a day apart, sometimes 5 minutes. If I remove the batteries for a few minutes it comes back to life (with a "Memory Lost" display), but soon freezes up again. Any experience with this problem? It's enough of a nuisance that I've been trying to replace it for the last 10 days.

Thanks, Frank