Finding those tapes must have been a trip. It reminds me of the time I dug out my old Talkboy from the attic and the batteries had leaked all over it. Total loss.

Tbh a little tap with a pen cap works for a sticky transponder IDENT button too.

So which tester do you actually trust then?

Hourly billing makes you overthink every minute. It's a trap.

Ever try to fix a squeaky door hinge and end up taking the whole door off the frame? That's basically what you did. I've had good luck with a tiny bit of lighter fluid on a stiff ring, it evaporates clean. But yeah, oil finds its way into everything.