Way back in the late eighties or very early ninetis, when the kids were little, my wife decided she wanted one of those newfangled microwave ovens so we went out and paid the big bucks for a 2 cu ft Quazar with all the bells and whistles. Within the first year, under warranty, they had to replace the rotating microwave antenna. (this unit moved the microwaves instead of moving the dish, which made the entire capacity of the oven useable - oblong pans were no problem)
About 5 years ago, she decided ahe wanted a new one - she was afraid the old one was going to die, and someone had a modern inverter type Panasonic on sale for a good price. I told her the old one would likely still outlast 2 or more new ones - but "happy wife = happy life" so we disposed of the Quazar and bought the new Panasonic.
For the first several years it was fine, but gradually over the last year and a bit, it was getting flakey - sometimes the light would not go out and the oven would not start untill you slammed the door hard enough to almost put it into the garage.
I took it apart this afternoon to see what was wrong, and found the latch assembly with the 3 interloc microswitches was mounted on a very thin and flimsey metal "ear" stamped out of the roughly 28 guage steel, and it had shifted position JUST enough that it occaisuionally worked. I bent it back to shape and got myself a 3 inch angle bracket, drilled it and cut it to size to rest against the metal front panel where it was flanged in, and screw to the "ear" that holds the latch.
Works now - and when it fails next time it WON'T be because the bracket/ear bent - I can pretty well guarantee THAT!!!