Do you ever look at the plugs on your appliances. Many electrical appliances around the home will have been supplied with a moulded plug top which is virtually maintenance free, but there are still of home fitted plug tops around. We see a large percentage of microwaves that come into our workshop with after market plugs fitted. Please check from time to time. especially if its a plug that gets used or moved around a lot as appliances such as irons are taken from or put into cupboards. Check that the plug top itself isn't broken. Often parts of it will break off as the material is quite brittle.I wouldn't expect anyone to take a plug apart for a routine check (that's our job. when a microwave comes in for repair we always check the plug top and cable for signs of damage), but if the lead feels or looks loose, then you should check inside. The screws can come loose or may have been fitted too loosely during fitting.
One of our technicians during a routine repair just recently checked inside to see several of the wire securing screws actually missing - not even inside the plug top.I could mention about how to wire a plug but its almost a topic in itself. For now check the first picture by the title of this post. That's pretty much what it should look like, at least what colour wires go where. Finally, If the fuse goes and you need to change it, please make sure you change it for the correct rating, replace it with the same colour fuse. Usually 13 amps for most kitchen appliances. If it blows again you need some expert help to check the appliance as there is probably a fault.