Emerson Microwave - arc from side panel

[bigcountrymdk1]

We have an Emerson Microwave Model number MW8109W that we have used for several years- primarily for light reheating of kids meals. Recently when heating a product with high sugar level, we noticed a pop/ and what appeared to be an electrical arc inside microwave. We removed product and did not experience the problem again until today, several weeks later. After removing (microwave safe) plate, and unplugging unit, I found burn mark on right side, above "metal" plate. I removed metal plate (approx 4 inch rectangular- slides out of "notches")- it has a melted spot in in with burnt appearance on same area of microwave interior. Repairable ?? Thank you in advance for any assistance or recommendation.

[HayZee518]

that plastic or mica insulator is a cover for the microwave waveguide. at the top of the machine is a hollow rectangular tube that goes to the "cavity" on the magnetron tube. the magnetron is what produces the microwave enegry to heat your food. what happened in your case, a hot spot showed up on that insulator and when the magnetron fired, it concentrated the micro waves on that one spot and ignited it. you can remove the piece and replace it with a thin piece of poly carbonate.

[bigcountrymdk1]

thank you so much for fast reply. i'll stop at the nearest home improvement store for a piece of poly carbonate today....there is a raised burnt spot approx 1/2 inch by 1/8 inch in side wall of microwave oven where the panel was laying against wall - is this a concern ? or should covering it with the poly carbonate be sufficient? thank you again.

[HayZee518]

remove it and replace it - microwaves are invisible and will penetrate the poly and just cause a recurrence of your original problem.

[Dan O.]

we noticed a pop/ and what appeared to be an electrical arc inside microwave.

Food residue (splatters, etc.) not cleaned from surfaces will continue to heat while in use. Once they're become carbonized (burned) they become conductive to microwaves and create sparking between the burn area and metal surfaces (the microwave interior for example). Splatters should be cleaned up religiously.

there is a raised burnt spot in side wall of microwave oven where the panel was laying against - is this a concern?

It shouldn't be a concern for microwave leakage unless the underlying metal has a hole. But all burned areas should be corrected before using the oven again. They will often just burn further when used again.


The following touch-ups can be used to repair microwave oven cavity finishes. For small areas the fingernail polish-size touch-up would usually do. For larger areas the spray touch-up usually does a more acceptable job.

LINK > Microwave Cavity Touch-up

LINK > Microwave Cavity Spray Paint

There is also universal 'wave guide' material available (see the following link) that can be cut to size to fit most original flat (non-molded) cavity interior covers.

LINK > Microwave Oven Wave Guide Cover Material



JMO

Dan O.
www.Appliance411.com
The Appliance Information Site
=D~~~~~~