I have had the same Daewoo microwave oven since I bought it new 7 years ago and it's always performed *perfectly* up until today. This morning I stuck some bread in it to defrost and it came out still frozen. No trace of any heat at all. The platter rotates, the light comes on, the timer counts down, the fan runs; all is working fine except for the total absence of heat. I'm given to understand that microwave ovens typically have a working life of only around 2 years nowadays, so I'd really like to fix this one up rather than replace it with something inevitably inferior. Any suggestions as to what to check for? I have the gear to measure up to50kV if necessary, and I'd guess the magnetron HT is considerably less than that figure. So... where to start looking first?