HP35s batteries problem

[mcjtom]

Hi,

I just got a new HP35s calculator, which came with two CR2032 batteries. I inserted the batteries (I believe properly). When the ON button is pressed, the display turns on, shows an empty battery symbol and then the calculator turns off after a few seconds.

I thought that somehow the batteries that came with the calculator were empty, so I just bought two new batteries. With the new batteries the calculator does exactly the same thing (i.e. turns on for a few seconds, shows empty battery sign and then turns off again).

What am I doing wrong?

Cheers!

[Joe Horn]

(09-06-2014 06:57 AM)mcjtom Wrote:  Hi,

I just got a new HP35s calculator, which came with two CR2032 batteries. I inserted the batteries (I believe properly). When the ON button is pressed, the display turns on, shows an empty battery symbol and then the calculator turns off after a few seconds.

I thought that somehow the batteries that came with the calculator were empty, so I just bought two new batteries. With the new batteries the calculator does exactly the same thing (i.e. turns on for a few seconds, shows empty battery sign and then turns off again).

Hypothesis: Since that's exactly what happens when only one fresh battery is installed (leaving the other battery compartment empty), I'd guess that either one of your cells is dead (unlikely but possible), or one of your battery compartments is not making a good contact. Try one cell only, in each compartment, then do the same with the other cell, to test this hypothesis.

EDIT: Needless to say, both cells should be installed with the "+" showing (positive facing up).

[mcjtom]

Thank you Joe, brilliant!

I did what you suggested and it seems that there is nothing wrong with the batteries. Instead, one of the batteries compartment does not work.

I concluded that because with a single battery in one compartment (the good one), the calculator behaves as before (i.e. turns on, shows battery empty, then turns off). But if I insert a single battery into the other compartment, the calculator is dead.

I gently cleaned the contacts with alcohol, but to no avail. That probably mean that there is some physical wire inside the calculator that breaks the circuit from this compartment.

Is there anything else that I could do rather than returning/replacing the calculator, which will be a drag as I didn't buy it locally?

Cheers!

[Thomas Radtke]

If you can solder, solder (new wires).

Lyuka did some nice shots:



http://www.finetune.co.jp/~lyuka/interests/calc/hp35s/