HP-12C+ show Error 9

[Gamo]

Got this HP-12C+ since 2016 this work all good no problem until recently I put a Prime Number finder program that let it keep running with a pause for each prime it find.
I let it run for about 45 minutes straight then the display show the digits fainted so I press any keys to stop the process then show "Pr Error" that's mean all my program is deleted.
I turn it off and back on and press f P/R the display shown blank nothing on the display. Turn on again now is normal I can do any calculations no problem but when go to Program mode the display will go blank.
I try the self-test and result return with "Error 9"
I checked the batteries both are good with a little bit above 3 Volt on both batteries.

With the self-test sometime will be able to go to program mode as normal. Put program in and run as normal but every once in a while you never know the Pr Error will show up and can not go in to Program Mode again.

To wrap this up: So is this not a good practice to do a long period looping program on Programmable Calculator?

Gamo

[Carsen]

(06-21-2018 09:56 AM)Gamo Wrote:  To wrap this up: So is this not a good practice to do a long period looping program on Programmable Calculator?

I don't think so. I bought my HP-12C in December of 2016 and I have run programs for about 50 minutes with no problems so far. For example, I wanted to see how quickly my 12C could go through all 500,000 random numbers in the random number generator.

[BartDB]

PrError is a sign of low batteries. When running programs or executing functions this calculator uses current that is high for coin cells, so you really need good batteries.

Put in new batteries, a good brand from a reputable retailer.

-Bart

[grsbanks]

(06-21-2018 09:56 AM)Gamo Wrote:  I checked the batteries both are good with a little bit above 3 Volt on both batteries.

If that's the voltage across the batteries when there's no load on them, it means squat.

As batteries age and run down, their internal resistance climbs. This means that the voltage across them dwindles for the same current being drawn from them.

I think HP usually put Maxell batteries in their machines and they're OK. What you don't know is how long those ones have been hanging around and how long they've been in your 12C. They're not expensive so don't waste any time thinking about the pros and cons, just replace them. With well-known branded batteries.

[Gamo]

Thank You for the reply to help figuring out the problem. Today I put a new set of batteries but this batteries is from IKEA brand for now.
All operations work perfectly no problem.
I'm still wondering why that it didn't show low battery power indicator. This batteries was original in box not the Maxell brand (Unknown Brand) and I used this same set of batteries for two years.

Gamo