Our over-the-range Samsung microwave stopped heating. No error messages, everything works, no different noises - just completely stopped heating on all settings.
I replaced a blown fuse, then (very carefully) the capacitor, diode, and even the magnetron. (Parts so far $80, new unit $300-$400.)
We've been keeping it unplugged. Now, the first use (coffee or leftovers) works great. Second use so-so, third barely warms, and then it's done. Unplugging for an hour or two resets it.
What could it be? Probably ten-plus years old, so is it just done for? Replace it?
My multi-meter skills are limited, but the things I could test seem okay. It's the intermittence / declining power that confuses me.
Thanks for suggestions. It's tough living like an Amish Cave Dweller and cooking with actual fire!