[thuythu]

Hi tech support, would you please help. None of the button on the control panel of my microwave oven worked, even clock, nothing work, all quiet. However, when the door is opened, the light bulb still turned on. I saw a forum which described the same symptom and the suggestion of changing a fuse, but after that, i do not see any feedback. anyway, would you please advise whether a fuse needs to be replaced in my case also and if so, then how can i get access to the fuse, so that i can change? also, would you please tell me what is the part number to buy. thank you very much in advance. Regards, Thu.

[Gene]

Thu,

Remove the top grille and open the control panel. Check for continuity the magnetron thermal cut-off (#14 on the diagram). If this part is not accessible through the control panel opening then you have to remove the microwave from the cabinet.

If the thermal cut-off is open then it has to be replaced and you have to make sure the cooling fan is working.

If the thermal cut-off is good then the problem is a bad control board.

- The part number for the thermal cut-off is AP4060517

- The part number for the control board is AP4062549

Here are the breakdown diagrams and Replacement parts for MAYTAG MMV5000BDW | AppliancePartsPros.com

Gene.

[thuythu]

Thank you Gene. I will try to open. However, would you please tell me how do I know the thermal cut-off open? Is there a switch in this part, would you please give me a hint? So, what you are saying is not a fuse's problem? What symptom would it be a fuse's problem? I am learning to fix things myself. Thank you very much again for your help. Regards, Thu.

[Gene]

Originally Posted by thuythu

...would you please tell me how do I know the thermal cut-off open?...

...So, what you are saying is not a fuse's problem? What symptom would it be a fuse's problem?...

Thu,

You have to check it for continuity. The following article on our forum will explain in detail how to run a continuity test using either an analog meter or a digital meter - How To Check Continuity With Ohmmeter

No, this is not a fuse problem. I mean this is not an IN-LINE fuse problem because the thermal cut-off is kind of fuse too. The only difference - this a THERMAL fuse which works by the temperature while the in-line fuse works by the current. In case if an in-line fuse blows the microwave is going to be completely dead - no noise, no lights, no display. Nothing.

Gene.

[thuythu]

Hi Gene, thank you for your help again.
I will follow your instructions and will give a try . Hope it is only the thermal cut-off problem. If it is the whole control panel, then no luck! It is not worth to replace the control panel, since I looked at the price, it is too expensive. In this case, it is cheaper to buy a new microwave oven. Regards, Thu Tran.

[Gene]

You are welcome. Keep us posted.

Gene.

[thuythu]

Hi Gene, today, I opened the control panel side, however, I could not locate the TCO as it was shown in the little picture (#14). I looked over and over again, the only mentioned TCO is on a yellow wire which connected to a 6 wire plugs on the control board, the yellow wire labeled (yellow) TCO H.D, then there are other 5 wires on the same plug which said like (red) COM MGT, (black) Geared Motor etc ... the other end of these 6 wires were connected to a rectangular blue plastic part with one blank button, this button seems to operate the open and close door and turn on and turn off the light inside the microwave. Other than that, I do not know where is the TCO part that you mentioned about. Would you please direct. Would you please tell me where the defected part near by? Is this right on the control panel or inside the cavity where it looks like the magnetron (#1) is located? Thank you very much for your clarification. Regards, Thu.

[Gene]

Thu,

It looks like a small tablet




and it is attached to the magnetron



Gene.

[thuythu]

Hi Gene, thank you very much again. I could not locate this part on the control panel, the magnetron looks big, it seems to me that it is inside the cavity behind the control panel. Am I right? I looked at the image of the TCO that you sent, it does not look like any attachment to the picture on the magnetron, so, it might be behind the magnetron that I do not see, am I right? For the TCO, it saw the 2 prongs, are these the ones that I need to put the meter to test for the open and close that you talked about previously? If my assumption is correct as above, then I would like to ask you how do I bring down the microwave oven from the cabinet? I could not see how was it hung? Please give me tips. Thank you very much again. Thank you for your patience to the novice. Regards, Thu.

[Gene]

Originally Posted by thuythu

...1. it might be behind the magnetron that I do not see...

...2. For the TCO, it saw the 2 prongs, are these the ones that I need to put the meter to test for the open and close that you talked about previously?...

...3. how do I bring down the microwave oven from the cabinet?...

Thu,

1. Very likely it is there.

2. The answer is - Yes.

3. You can find the complete instructions in the Installation manual.

Gene.