04-10-2019 02:37 PM
You needed reset the calculator, with ... ON+F1+F6 or with the point of one paper clip, in the Reset orifice, site in rear case.
For determine the battery charger, you can install the BtMon 1.0, from ... https://www.hpcalc.org/details/6587
You're Welcome !.
Best wishes and regards.
@Maké (Voluntary and "ad honorem").
Click the White thumb to say thanks.
Please, mark Accept As Solution if it solves your problem.
PD : The experience is a comb that you are given, when you have become bald.