Maytag mmv4205baw will not heat and is making a louder than usual sound. All else appears to be okay.

William Miller

• 9179 Answers
• Posted on Nov 30, 2007

SOURCE: maytag mmv1153 no heat

In this case I would suspect a bad high-voltage recitifer diode or magnetron (due to the louder sound) but...

Generally, the most common causes of a failure to heat are:

- bad door switches or door switch mounts
- loose connection at the magnetron
- problem or loose connection on the control unit circuit board
- bad magnetron or other high voltage part

If you or a friend decide to look into it, we have critical safety information, info on door switch diagnosis and replacement, and
disassembly information at our site, linked here on Fixya: http://tinyurl.com/yzjozk

You can usually find helpful exploded view diagrams and order parts by entering your full model number here: http://tinyurl.com/gv383

Please write back with more details if you need further help.

We're happy to help and we appreciate your thoughtful rating of our answer.

SOURCE: Microwave no longer heats, makes more noise than

Sounds like the magnetron has failed. There are some high voltage circuits that feed the magnetron and you can potentially get hurt if you don't know what you are doing. Would recommend you have it serviced by a professional if you want it fixed, otherwise look for a new one since the cost of repair can come close to the price of a new microwave oven.

Testimonial: "Thanks, I talked to the manufacturer and they suggested the same. Thanks for taking the time to reply."

SOURCE: maytag microwave MMV4205BAW interior fan continues to run when door is closed

One of the micro switches has malfunctioned, and must be replaced for normal operation.

Testimonial: "Thanks again! I was afraid of that. Probably a bad relay but you have to purchase the whole board and that looks to be a $200 part. Guess it is time for a new microwave."

SOURCE: I have a maytag built in microwave MMV4205BAW from August 2006. The microwave runs but does not heat and makes a slight buzzing sound. It sounds like the magnetron needs to be replaced. If this is not

From the description it is the magnetron, it will be expensive for the part alone, and keep in mind shops have different rates making impossible to give exact quotes, but I would estimate parts and labour at least $250.00 or more, if you decide to go with the repair make sure the magnetron is not a aftermarket product it will last about 6 months.