[jamie432]

My microwave oven that is part of a built-in combination oven just stopped working as it was heating some food. Now it is totally dead with apparently no power to it, no lights coming on, and no response from the control panel. The lower electric oven works fine which seems to show that the unit as a whole is receiving power. I am wondering if the microwave has blown a fuse. (I have had this for 12 years and this is the first issue I have experienced with it).

Can anyone tell me how to access the fuse for it to check if that is what is causing the problem and if so, where would I be able to get a replacement fuse for it? If anyone can point me to a sketch or drawing for it that would really help too.
Thanks a lot.

Correction to post:The correct and full model number for the oven is RM770PXBQ2. Sorry for the error!

[sarcastic tech]

There several in the unit. I couldnt pull it with the modle # provided but most have one. I would have a tech come out and have a look as to which one it is. Also, personally, I DO NOT reccomend someone opening up a microwave that is isnt knowlegeable. Its kind of like the game " OPPERATION" we had as a kid. It takes a steady hand, and instead of the nose lighting up when you touch something you shouldnt, a MW can put several thousand volts through you. It WILL throw you across a room....if you are lucky, you wake up.

[jamie432]

sarcastic tech,
Thanks for the warning! I'll keep that closely in mind. I know my way a little around electrical and electronic units if I know what I am looking for. I corrected an error in the model number for the oven that I had posted. The correct # is RM770PXBQ2. With this correction will you be able to pull more information and perhaps shed some more light on it for me? Will really appreciate it. jamie432

[sarcastic tech]

I know there is a fuse ( 20A I believe) with the part # 4365543. I thought there was a bigger brass colored one as well on that model but cant find the info to support that. If its just the lil 20A fuse (either grey or white) that will give you a blank display. If you see a larger brass one ( going from memory in the right rear of the top of the unit) check for cont. on that one too.

[jamie432]

Originally Posted by sarcastic tech

I know there is a fuse ( 20A I believe) with the part # 4365543. I thought there was a bigger brass colored one as well on that model but cant find the info to support that. If its just the lil 20A fuse (either grey or white) that will give you a blank display. If you see a larger brass one ( going from memory in the right rear of the top of the unit) check for cont. on that one too.

Thank you for the info. One other problem I am facing is that the microwave unit is pretty heavy and too tight a fit to work on while it is sitting in its housing above the electric oven. Is there an easier way to get to this fuse, other than pulling it completely out of its housing, disconnecting its wire bundle, removing the the top cover and possibly removing the control panel as well? Or is there some other access door to the fuse?

[sarcastic tech]

Thats it. If you can get the control panel off you should be in the clear.

[jamie432]

Located and replaced the fuse. It was a 20 amp time-delay fuse. The panel light came on and the inside light also came on when the door opened. But when I tried to to test its operation putting a glass of water inside, just as before it ran for a couple of seconds, made a relatively loud buzzing noise and everything shut off again. So the fuse was not the cause, just the symptom of something else.
Can anyone give me any ideas? perhaps a high voltage transfomer or something else? how can I test that?