Emerson microwave 1100w. When turned on everything works and a loud buzzing starts and does not cook.

Yes, it wont make any difference to the cooking . It will just be harder to see inside when the food starts to burn or boil.

It is better to replace as the cost of repair is high.

I've had an Emerson microwave/grill for about 5 years now and love it!! To use the grill function you just hit "grill/combo" then hit the buttons up above the grill/combo button for however many minutes or seconds you want, then hit "Start" button. make sure your using a metal dish.

see this causes and fix it. God bless you
Magnetron If the microwave is loud or noisy only when cooking, the magnetron tube might be defective. The magnetron uses high voltage, high current DC power to generate the microwave frequency that cooks the food. Under normal circumstances the magnetron is nearly silent. However if it is damaged or nearly burned out it can begin emitting high pitched or growling noises. It's not normally dangerous to use a microwave oven when it makes these noises, but they are an indication that the magnetron is almost dead and will need to be replaced.
Exhaust Fan Motor If the microwave is loud when running the fan motor might be
Stirrer Motor If the microwave is loud or noisy the stirrer motor might be worn out. The stirrer is a metal blade which slowly turns around, deflecting the microwave energy in a random pattern inside the microwave oven. As the motor nears the end of its useful life it begins to make grinding noises. The microwave will not heat food evenly without this stirrer, the motor should be replaced.
Turntable Motor If the microwave is loud or noisy the turntable motor might be worn out. This is a common problem and relatively easy to replace.

there is a thermal (white ceramic) fuse located right under the cover on the top of your microwave replace it.
an electronics part store should stock it.

Replace the fuse with a ceramic fuse from Home depot! costs less than $3 and it will fix the problem. I had all the same problems as everyone else, you name it my microwave had it! you must remember replace it with a ceramic fuse! not a glass one. I know people say its the switchboard and all that nonsence but I promise you, the fuse plays a majoe roll in the microwave not working properly. Even though it doesnt look broken, a junky fuse can cause your appliance to do very strange things. I replaced mine 6 months ago and it works like its fresh out of the box.

WHAT IS WRONG WITH YOUR MICROWAVE?

For a detailed Microwave illustration, click below.

Counter top
Built in
Danger! You can receive a serious electrical shock from the components inside your microwave oven--even when it's unplugged. Only a qualified appliance repair technician should perform any repair.

It doesn't work at all
It sounds normal, but there's no heat
I can't adjust the power level
The carousel won't turn
I have intermittent cooking problems
The display flickers
There's no heat, but it buzzes loudly
It quit after I slammed the door
It looks like there's lightning (arcing) inside my microwave

hope this may help;

Regards,
VOTIT

DON'T FORGET TO RATE;

Some units have a silica plate covering the waveguide opening. If it get burn spots on it, it'll do that. Remove the plate and try the unit. If it's OK, go to your MW repair shop and order a new plate.

Remember... always cover your food...

Geno

I have a GE counter top microwave oven. When the oven starts cooking (the magnetron turns on) the oven makes a harsh buzzing noise. What is wrong and what should be done?

Have you tried putting a cup of water in it and cooking on a low power level? If it buzzes only when it is on the cook cycle, that would narrow it down. More detals might help us help you, including the model number.