HP34C battery polarity

[Zaphod]

Dagnammit

I tried a couple of used AA primarys I had knocking about, calc powered up.

Was playing with it for 10-15 minutes - all aok, then suddenly half way through keypresses the display died !!

I thought for a moment the batteries had become dislodged, but double checked and they were fine, I'd used copper take at the other end.

The calc is now dead to the world, terminal volts are pretty much spot on 3V....

I double-checked that people have used these with primary cells
(https://www.hpmuseum.org/cgi-sys/cgiwrap...read=15985)


So what's occurred I wonder?? - any ideas?

(The calc weighs ~175grammes to tell you which type it is/was)