Thanks ... got it done.

Very sad about your fires .... we spent time around Katoomba a few years back on vacation. Glad it was spared but can't imagine the destruction to that area

Really a simple ( dumb) question I think ... I'm replacing batteries to an older Argo control model ( dark blue 102B ).
Before replacement of the AA batteries ... no display when switched ON.
After replacement of the AA batteries ... normal looking display & operation when switched ON.

As I get no BATTERY FLAT display I assume the 3V lithium battery still is good.
But, I want to replace the 3V as I do not know its age.

Reading the manual: I just open the hatch and replace it ( being careful of static issues ).
I assume the the controller ON/OFF switch is in the OFF position .... YES?

Or, should it be ON (to supply voltage) when the 3V lithium is out of the holder so I don't lose memory?

Brooks