It's also a fire danger because the mechanical time wheels can lose spring tension / get gunked up just enough to stick right before they reach the end, leaving

It's also a fire danger because the mechanical time wheels can lose spring tension / get gunked up just enough to stick right before they reach the end, leaving the microwave on until you notice. It wasn't a huge deal when it happened to me because I wasn't very distracted and I was making tea so it just sat there and boiled for a couple of minutes until I checked in. Under slightly different circumstances it could have been much worse.