[Daryles]

What causes the fuse to blow is a safety interlock with the door switches to prevent the microwave from operating with the door open.
Try changing the door switches (parts listed above, not hard).
If you want to delay the inevitable,
Turn off the microwave circuit breaker each time before you open the door. After you put your food in the microwave, close the door, turn on the breaker and run the microwave. When it's done, again turn off the breaker before you open the door.
It's a pain but it works.