My whirlpool gold microwave model GH4184XSB-1 stopped working after a paper plate caught fire inside. I replaced the wiring going to the thermal overload and the thermal overload but it still doesn't work unless I jumper the overload? Is it connected to another overload in series? All fuses checked out ok.

If is an over range model and a good make, yes it is. If it is a counter top microwave oven made by Hinari, no it isn't. If it is a Sharp or a Panasonic and is less that 20 years old, it is *probably* worth repairing. You will get sparks and smoke if you use plates that are decorated with gold or silver. The microwaves react and burn it off. Don't put those plates in the microwave, or use low power.

'make model (what it is)' as the first three words in every question please. :>D

Microwaves work by friction. They blast water molecules in the food so they move fast, just like rubbing your hands together makes them hot. Some types of microwave in defrost mode actually apply FULL POWER for a short period of time so to make the product warm to the touch. This heat then penetrates down to the core of the food, ensuring full defrost. In your case the heat was sufficient enough to heat the dry paper towel to set it on fire.
Bread is better defrosted on the low power setting as sliced bread is very thin. Items should only be defrosted on the defrost setting that are thick and need to be completely defrosted on the inside. Remember microwaves only penetrate the surface of food, making that hot. Thermal conduction does the rest.
You should never use paper towels in a microwave unless the instructions for doing the food say so. You wouldn't put a paper towel in a gas or electric oven, so don't put them in a microwave.

usually caused by grease build-up inside the cavity

I haven't heard of such a thing. You must have cooked it until there was no moisture left in the potato. That would also account for the failure of the oven. It would be the same as no load in the oven.
A thermal protect part is your current problem.

there are short. go to www.repairclinic.com for to get the parts.
2) test the switch door for short and replace see the diagram
3) test the high voltage capacitor+ high voltage diode
see the diagram

Time for a new cover plate or a new microwave. Depending on the age of the unit, the part may not be available anymore.

Hello, inside most microwaves, there is a thermal fuse, that if something in the cooking cavity is on fire, it will melt the thermal fuse, if it gets hot enough, thus breaking the power to the unit shutting it off. This sounds like what has happened to yours, simply replacing it will correct the problem. It is usually located near a cavity exhaust point. If you aren't comfortable doing this, as it requires removing the outer cover, while unplugged, and locating/replacing it, take it to a appliance service co. This will of course cost more, if you do it yourself, make sure you provide all of your make/model/serial/anything else, that will identify your unit, and call/go online to a parts retailer, and you should be able to get it done fairly cheap.

Hope this helps, and thank you.

it may be ok , but it should be checked for internal damage

Was the ceramic plate part of the microwave or a plate form the kitchen?

If it wasn't the microwave plate, it should be fine. You should be able to be sure it's all clean and use it as usual.

A microwave oven should of course never be left running unattended, especially when using any paper products.

Paper plates and paper towels can sometimes have small amounts of impurities which can ignite.

This is covered on page 1 in your owner's manual, which can be downloaded here.

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

inside microwave oven may be wiring damage check wiring and contorl circuit,