HP42 Machine reset - what's going on

[Guenter Schink]

Recently I acquired an HP42S on TAS. It was rightfully announced as defect to show "Memory Reset" at arbitrary intervals.

The HP42S was only about 30EUR (33US$). That made me think, no risk no fun!

Unpacking the device and switching it on made it beep and show "Machine Reset" right away, so no surprise. Consequently the seller deserved a positive feedback, as the description was awfully exact.

First positive sign was, pressing between the display and the keyboard, made the noise stop and I could make the HP42S work as expected for a while. But then the nasty behaviour showed up again.

Asking the everything knowing WWW for "machine reset HP42S" I found a few threads, most of them at hpmuseum.org, specifically for this problem, but nothing was really enlightening.

Restarting the calc every now and then, putting it in coma mode, running it in almost endless loops, pressing it here and there, caressing its back, and what have you, made it obviously work, for what reason ever.

Now, for 4 days it worked flawlessly. Never showed the nasty "Machine Reset" again. I'm wondering: did my magic hands rectify the situation, was there some magic action I did, or will I simply have to wait for the next failure to occur?

Thanks for reading my report so far,
Günter

[Katie Wasserman]

Check that the batteries are good and clean the battery contacts.

[Guenter Schink]

(01-08-2016 11:39 PM)Katie Wasserman Wrote:  Check that the batteries are good and clean the battery contacts.

Thanks Katie,

I followed almost all the suggestions published here on the forum in the past. Yet I'm not going to open it. Maybe I'll give at a door prize at the next HHUC.

Günter

[aurelio]

(01-08-2016 11:39 PM)Katie Wasserman Wrote:  Check that the batteries are good and clean the battery contacts.

If that's all, what a bargain for Guenter!!

[Guenter Schink]

Update

I had the HP42S run now for a couple of days without problems. That is, occasionally I switch it on 3-10 times a day and let it run a short program with 10000 loops.

But today all of sudden it came back beeping again.

While I could manage to get it alive again, the "Memory Lost" was not really convincing. However this time it didn't show "Machine Reset".

So for now, it is a very capable calculator, but not really reliable to store large programs in it.

Günter, not complaining as still it was a bargain.