In my grandpa's workshop, he kept a coffee can full of old batteries and scrap wire for exactly this kind of fix. I see a pattern where that whole generation had a knack for solving problems with whatever was on hand. My own uncle taught me to test a wall socket with a lamp bulb and two wires, no meter involved. That basic, touch-and-feel approach is a dying skill now that everything is digital. In my experience, keeping that hands-on logic alive saves money and feels rewarding. Your mileage may vary, but it's worth trying to learn a few of those old tricks.

Took me forever to learn that lesson too.

Wait, are you telling me your thing actually sounds pissed off for months on end? That's crazy, @the_wren. I mean, what does an angry noise even sound like? Is it like a harsh screech every morning or a low grumble all day? My neighbor's old AC unit used to make this awful rattling sound that felt like it was yelling at the sun. I can't imagine dealing with that all summer without losing it.