97S low battery Indicator with no display

[Hiwi]

Regarding the adv knob: 2 wires are connected when idle, open when pressed, then the other pair is connected.

Do you have a multimeter on hand? I would check the transistor before turning on again. There could be a faulty tantalum nearby. Or one of the zeners.

I willl check the service manual and look what this transistor does. And most of the HP-97 transistors can be replaced with standard common NPN or PNP transistors e.g. 2N3904


Ralf