Slow Microwave

My microwave is from 1990 vintage. Back when my studio was at a mill complex, away from where I lived. I had a mini fridge and I made hot lunches for myself. Often it was a casserole of corn and spinach and eggs. The brand is Capri and it's built like a tank but it is so slow that while I am heating up my lunch I usually make a sandwich. By the time my lunch is hot I am done with my sandwich and I have to put my meal back in the fridge. I don't want to buy a new one because they are expensive and bulky and ugly.