Really, Guys! lol! Usually when a microwave 'dies', it is the Magnetron that needs replacing. There are a number of websites (Google it) that sell magnetrons and also include the fitting instructions - it's just slightly more complicated than fitting a new bulb (no, please...no "how many ... does it take to fit a light-bulb" jokes ! ).
Jack the transformer and make a Jacob's Ladder or something instead. Oh, and don't die.