Go on Amazon - or go down to a Business Costco or whatever similar restaurant supply place (that sells to the public) is available in your area - and purchase a commercial microwave; Sharp or Amana are the ones most sold.
My wife and I got sick of our microwave always dying after a few years, plus having a ton of "features" we never used. Too many buttons, too much complexity, and too expensive to be buying year after year. So we went with a commercial 1000 watt microwave:
1. It has only a single knob to set the time limit in 15 second intervals - up to 6 minutes.
2. No turntable to break, clean, or wear out.
3. One cooking level - HIGH.
4. An interior that is super-easy to clean - just wipe it out, all surfaces are smooth and seamless.
It's only real downside is the fact that the light doesn't turn on when you open the oven door (it's only on when it is cooking).
Other than that, it's been a joy to use. It takes a bit of getting used to not having cooking levels, but other than that - it's not an issue. The trick is knowing that in a regular microwave, "cooking levels" are done in a "slow PWM" fashion - a duty cycle of the magnatron - so much turned on for so long, then off for a period. You can simulate that yourself if you have to, but we usually just thaw things in our fridge ahead of time (or put them in our sink or on the counter).
Not having a timer that can go more than 6 minutes also means you have to be paying attention if you are doing something long-term (cooking rice or something); just pull it out, stir it, pop it in for some more time. If you have to rotate something for even cooking, do that manually too.
Less functions, less parts, less junk to wear out, clean, or break. Win, win, win. Unfortunately, it wasn't cheap - but given we were replacing our microwave every 3-5 years, it'll pay for itself in a short amount of time.