Doug Warner wrote:
My 8-10 year old Sharp microwave oven has died from a shorted HV
capacitor. I'll probably fix it, if the part is still available.

If not, I'd like my next oven to "listen" to popcorn, and shut off
after the popping rate slows to a threshold level. My current oven's
popcorn mode always comes up about 40 seconds short.

Why don't you just set your microwave timer to pop 40 seconds more than
the popcorn mode?

Or is pressing 4 more buttons too much work for you?