"I have heard it said on here by a microwave service guy that a broken door switch can cause the microwave internal fuse to blow - I find this difficult to believe but I can't ignore his experience."
Think he's right. Opened door last night - WHAM. ELCB tripped and found exploded fuse inside microwave. There are three door interlock switches. It looks as if , if one of them opens before the others, mains live gets connected to mains neutral momentarily. That's why the specified fuse is a slow-blow ET8A, probably. The previous occupant had used a bit of fuse wire wrapped round the remains of a quick-blow F8A. May buy new nuke anyway...
Baal
February 2016