I have a Magic Chef MCO153UB. When the unit is used to cook for 5-10 minutes you hear a distink change in the way it runs, the light stays on and the table still turns and the fan runs, but cooking stops for awhile until the machine cools down(?). Have you ever heard of this problem?

This one actually sounds like the unit is cooking when the door is closed without blowing the fuse as it is supposed to do. Unplug it from the wall and let it cool down, which it probably already is. Put a cup of cold water in it, close the door and plug it in for one minute. Unplug it from the wall and check the water. Did it heat up? I'd bet that it heated the water up. Sometimes the cook relay sticks closed and it stays in cook mode. This condition is supposed to blow the fuse but really rarely it doesn't. I've only seen this happen 3 or 4 times out of about 14,000 units I have looked at in my career.
It would need a new control PCB and new door switches and probably a new magnetron.

Depends on the extent of the damage, disconnect unit from the power supply and be ready to use a lot of elbow grease. First use detergent that can clean grease. Do not use abrassives. You keep cleaning with Easy Off Bam or similar. If still looks aweful, decide to keep or change.

It appears the problem is in the keypad controller board, it will only run for 7 minutes and give a loud beep, you need a professional for this, to assess the situation.

it is an internal fan that is the problems, if this is a counter top MW just replace it. if Over The Range (OTR) and under warranty call for service. if out of warranty replace.

Sounds like a bad magnetron, i would replace the magnetron, Capacitor and Diode at the mag assembly, to be honest it will cost you more to fix than a new one.............

Right, that would be MCO10UW and the owner's manual is here.

The owner's manual does say this, of course,

"To prevent overheating from taking place, the exhaust
fan is designed to automatically turn on at a low speed if
excessive temperatures occur. Should this happen, the
fan cannot be manually turned off, but it will
automatically turn off when the internal parts have
cooled. The fan may stay on for up to an hour after the
range and microwave oven controls have been turned
off."

That;'s standard on microwaves.

But these models do have a separate internal cooling fan (which should run any time you microwave) plus the hood vent exhaust fan, which should only run when you select it, or if there is an excessive stovetop or under-hood temperature.

So if it comes on whenever you microwave, that is incorrect.

When that happens, it's usually a defective vent thermal switch (a.k.a. hood TCO).

But since it's brand new, I would certainly contact Magic Chef about this. If it's in need of repair, they will fix it free, assuming the oven wasn't physically damaged.

For more help from Magic Chef / Ewave see here or their contact page.

For Magic Chef in Canada call 866.587.2002

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

I returned the item to Home Depot and they took it back no questions asked.

Hi,

You are running the risk of damaging the Magnatron by doing this.

Check the packets you are using, you will have to reduce your power output.

This is because microwaves act by being absorbed by water. There is very little in popcorn and in fat. Once this has been evaporated, the microwave energy builds up (as it is still being produced - but not absorbed), and ends up cooking the magnatron itself.

I have seen countless posts on here after cooking popcorn!

More fun on the hob anyway - and cheaper to buy in bulk!

The first thing to try is a "hard reset". Unplug it from the power line for a few minutes, plug it back in, set the clock, then try again.

Please reply back here and let us know if the hard reset doesn't fix it.

It may have a bad door switch, and we can help you check into that. The first test for that is to try it while gently lifting up and then while gently pushing down on the door.

If you don't have your owner's manual, you can download it here:
http://www.mcappliance.com/products/otrdetail.asp?record=yes&modelname=MCO153UB

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

Fan turned on after cooking because a thermostat got to hot and tripped turning on the fan to try to cool the unit.  The unit went completely dead when thermal fuse tripped which is located above the cavity on the left side.