HP48S strange behavior

[Daniel Sole]

Hi all,

After many years having my old HP48S in the drawer, I missed using it again.

I have put new batteries and although it starts up perfectly and apparently all the buttons are good, it shows a strange behavior.

For example, if I press 1 + ENTER, it enters the stack as -1 (as negative). If I press 7, it seems to do the SIN function. If I press 0, the calculator enters the algebraic mode.

I dont know. Seems strange to me. It has always been stored in an appropriate place. When I found it, the batteries had made some salt, but nothing serious.

What do you think? Should I say "the king has died"? Tks!