Frigidaire Buzzing Fan/hood problem

[ngoirish]

Hello. I have several strange symptoms all ocured at once. on my microwave. The oven turns on and heats, timer works and clock works. Tested all the cooking features for several minutes and it is heating and dish spinning. but there is a constant buzzing noise that changes from a lower to louder buzz if the light button is pushed. LCD seems dim also, almost flickering at times and the fan/hood seems to have stopped all together. ANy ideas would be appreciated. Thanks