Problem began when I lost power and used a generator to run a microwave oven. The oven made a buzzing noise with chatter and heating power stopped. Everything else still works. Assumed magnetron bad and replaced with a new one,wrong, still did not heat, no power surge from magnetron when energized. Checked interlock and monitor switches, capacitor and diode, transformer, 20 amp fuse (if blown nothing would work), all ok. No burn marks evident anywhere. However, there is a very slight burn smell from noise filter PCB board. What are the chances that this board is bad? Any other suggestions please advise.
Thanks

Thanks ApplianceJunk. The magnetron is new so it is not the problem. If you believe control board ( smart board? )then is there a test to prove defective? If control board is bad then is it still possible for all functions to work? Can you confirm part# for a new control board? Thanks again.

Thanks for reply MicrowaveDisplaydotcom. I found out the hard way not to use microwave with generator running. I wonder what other appliances should not be run with generator on, any advise? I replaced the smart board (control board) and all works like new. Board is not cheap, but I was determined to find the problem. I am hoping to find what component failed on old control board. Thanks.