Why MEMORY LOST When turned on?

Discussion around the SwissMicros DM41X calculator
Chumango
Posts: 17
Joined: Sat Apr 10, 2021 6:00 am

Re: Why MEMORY LOST When turned on?

Post by Chumango »

Yes, it does help that there seems to be a likely explanation for the behavior.

The rub is that the question still remains of how do you know when you need to change the battery to avoid this problem to begin with? If my usage pattern remains the same I think I can gauge that. However if my usage pattern changes, which does actually seem likely for me, when do I change it? How much does usage need to change before I adjust battery replacement frequency, and by how much? I figure that mine got at most the equivalent of a few minutes a day, 5 days a week, for 8 months, and probably saw less use than that. Keeping track of actual usage to gauge replacement time would be challenging, and it seems that once a year may not be often enough. There's someone else in this thread who in one year's time has had to change the battery twice. The bottom line is that the battery indicator on the calculator has very limited utility for determining this.
HPMike
Posts: 439
Joined: Fri Jul 21, 2017 11:01 pm
Location: DFW, Texas

Re: Why MEMORY LOST When turned on?

Post by HPMike »

I agree with @Chumango that the battery indicator on the DM41X by itself is rather useless, and that the DM42 style which has the option to also show the voltage value is far more useful.
DM15L, S/N 00548. DM42, SN: 00159. DM41X, SN: 00973. DM32, SN 00054.
Peet
Posts: 256
Joined: Tue Sep 29, 2020 12:01 am
Location: Germany

Re: Why MEMORY LOST When turned on?

Post by Peet »

I've also found my DM41x in this "status" a time ago, when it first happened I thought the calculator was defective, but changing the battery luckily helped.
HPMike wrote:
Sat Sep 24, 2022 6:14 am
... the battery indicator on the DM41X by itself is rather useless,
Even the letters "BAT" if you should replace the battery would make more sense than three bars not saying anything usefull.
HPMike wrote:
Sat Sep 24, 2022 6:14 am
... the DM42 style which has the option to also show the voltage value is far more useful.
I also miss the volt display on the 41X. It would be a little bit more informative if at least the voltage at which a bar is subtracted were known.
My programmable calculators - former: CBM PR100, HP41CV, HP28S, HP11C - current: HP48G(256kB), HP35S, Prime, DM41X, DM42
rprosperi
Posts: 1698
Joined: Mon Apr 24, 2017 7:48 pm
Location: New York

Re: Why MEMORY LOST When turned on?

Post by rprosperi »

I'll add looking at including the voltage in the 41X's status display in some potential future update, but can't commit to this. Of course the code exists, but the wrapper DM41X and DM42 DMCP 'applications' are rather different, and it's not a matter of just dropping it in. Still it's worth a look.
--bob p

DM42: β00071 & 00282, DM41X: β00071 & 00656, DM10L: 071/100
ric8206
Posts: 1
Joined: Tue Oct 04, 2022 9:45 pm

Re: Why MEMORY LOST When turned on?

Post by ric8206 »

Hello, it's only a battery level problem, i had the same pbm and changing the battery solves situation(mine was 4/5 on level indicator but sometimes in use less). It's not only a problem of Volts but Current too, Nattery level seems to be ok or pretty good but in use the current is not enough and this conducts to a boot error in memory
Best regards, Eric ;-)
glancaster
Posts: 2
Joined: Sun Jan 23, 2022 11:24 pm

Re: Why MEMORY LOST When turned on?

Post by glancaster »

I've had this a few times as well, but on my DM42. It was dropped once (soft landing on carpet) but don't think the other times related to any physical misadventures. I changed the batteries after the first occasion so don't think they can be the issue.

So far my DM41X has behaved perfectly, however.
clark.ty@gmail.com
Posts: 16
Joined: Wed Jul 24, 2019 11:29 pm

Re: Why MEMORY LOST When turned on?

Post by clark.ty@gmail.com »

I got my brand new DM41X and had the same issue. Ultimately I had to replace the battery and then all was ok. Rather obnoxious for a $200 calculator to be shipped with a failed battery but them's the breaks. I also had a similar thing happen to my DM42 which I've had for a few years. Bart indicator didn't show low voltage but it crapped out and kept clearing memory. Replaced the batt and all is well again.
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