Small fire in above range microwave, now completely dead.

Only happens when cooking a big pot under the microwave? Hosing thermal fuse / thermostat kicks in to cool the microwave. Is the micro. Installed proper height above the range? Are you using the fan when cooking on the range?

If "everything" works and your microwave just stopped heating, the problem might be with the internal door switches, the high voltage circuitry, or the circuit board or quite probalby your magnetron is dead. If you don't have the technical knowledge to repair microwaves, you should take it to a repair service for diagnostics.

Microwave Ovens have a termic or ceramic fuse they open up when a overload occurs you must take it to a shop for reapair as microwaves handle hi voltage and amparege and is very dangereous.

Yes! that is exactly the problem, the fuse is a ceramic type "white body with silver ends" located near the high voltage capacitor, unplug and allow 30 seconds for the capacitor to dis-charge before removing the fuse. Keep in mind the reason for the fuse to blow is often caused a defective door switch, or you just might get away with changing the fuse.

where is the ceramic fuse located in an emerson micro. mw8991sb

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Fixed this problem! The door latches were greasy and sticking in the closed position (i.e., pushed down so not latching and engaging fully when the door was closed) and this created the problems described above. Solution was to squirt some Windex into the latch holes to dissolve the grease. The switches popped back into position (must be spring-loaded) and the door closed and latched properly, allowing the oven to function properly. I swabbed out the hole with a q-tip, let it dry for 20 minutes and all is well.

So it's dead - that is to say no display, no lights, and no response from the keypad?

A microwave can be dead for many reasons.

If it goes dead for a while during or after cooking then comes back on, the magnetron is probably overheating and causing the thermostat to open. When it cools, it closes the circuit and allows power through again.

If the fuse is good, it may be an open thermostat or thermal cutout on or near the magnetron or on top of the cavity / body of the oven.

If you or a friend decide to look into it, we have critical safety information and disassembly information at our site, linked here on Fixya: http://tinyurl.com/yzjozk

Please write back with more details if you need further help.

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Just so I understand, you replaced the fuse inside the oven? If so, I would suspect a bad thermostat attached to the magnetron. This device interrupts power when the unit gets too hot. I've included a representative photo. After so many years your magnetron may be bad, too. Once you get the oven working, if it cooks and doesn't trip the thermostat again, it may be okay. PLUS - It looks like this model has manual rotary controls. If so, it's common for those to develop bad contacts after so many years. I would consider that my third suspect. Those controls are called the thermostat (not to be confused with other part by that name that I discussed above) and the selector switch. One could easily be bad. You can check part prices at Sears online at http://www3.sears.com (the "3" is supposed to be there) Some other things that can cause a "dead" condition: - bad connections on the small circuit board where the fuse is mounted (if such a board is present) - bad connections in the wiring Good luck.