HP80 battery pack voltage reversed

[Jeff O.]

(11-03-2016 01:31 PM)elgin113 Wrote:  Thanks very much for the replies.
I reversed the battery pack now so the positive is on the bottom tang of the connector in the calculator. The pack has just below 4 volts dc and just plugged the battery in and didn't power on. I also tried 3 aa batteries and still no power.
I then read a HP calculator repair site and it said don't reversed the battery pack but didn't say if it damages the batteries or the charger.
I checked the charger voltage and one side says about 4.5volts and the other about 16 volts.

Not sure what do next?

Those sound like normal charger voltages. Did you ever turn the calculator on with just the reversed battery pack installed?

Also, just to cover the basics, did the calculator ever work while in your possession? Off of another battery? Off of the charger with no battery installed? (No harm will come to the calculator operated off the charger with no battery installed.) Did you try jiggling the on/off switch?