HP-33C strange power / weak battery indicator problem

[teenix]

Check for voltage drops along the power supply ribbon cable. There could be corrosion under the rivets that hold it to the battery terminals on the small charger board or cracks in the ribbon cable.

If so, this may be reducing the voltage to the rest of the calculator fooling the battery monitor circuit inside the CPU chip.

The 8 pins chip is for RAM memory and shouldn't be a problem. If so, it may get warm if it has a fault.

cheers

Tony