Question about Sharp R-340 Microwave Oven

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Location of monitor switch for Sharp R-5A54B microwave

The fuse blew on my Sharp R-5A54B. I replaced it and it blew again. The sticker next to the fuse says that when replacing a fuse you should also replace the monitor switch. Can someone tell me which of the three switches this is?


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Re: Location of monitor switch for Sharp R-5A54B...

The monitor switch is the middle switch. It is manufactured by omron and is a common type cherry switch. The omron part # is V-16G-2C25. The switch is a bottom type common terminal position with the contact form being a SPST-NC. Test the switch first with an OHM meter. Open the microwave door and you should have continuity between the two terminals. close the door and the continuity should be gone. P.S. The fuse may be purchased at any radio shack for about $3.00 pack of 4. their cataloge # is 270-1040 GOOD LUCK!!!!!!!!!!!

Posted on May 29, 2011

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Re: Location of monitor switch for Sharp R-5A54B...

It's usually the one in the center, as opposed to the being near the top or bottom edge of the door.

The entire service manual is available for free download on the Sears parts site (page by page) at (the 3 is correct)

Just look for the switch as ref # 1-7 on this diagram:

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

Posted on Dec 31, 2007

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The fuse is connected directly in series with the monitor switch. If it senses one of the door switches bad it will blow the fuse, this is there as an added safety to make sure the oven will not work without the door closed.

There are usually three and sometimes four door switches just inside and to the left of the control panel that are activated when the door interlocks with them. One of the switches is most likely bad. Typically it is the primary interlock which is on top. It can be checked with an ohmmeter, usually you can see it broken as the plunger will not go down or come up like the others.

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