How can you tell if a fuse is blown in my microwave oven? the fuse is solid white and has a gray line going around the fuse

You may have a bad fuse. It should be located behind the control panel. The fuse will look like the old auto glass fuses about 1/4 diameter and 1 1/4 inch long but made out of a ceramic material you can't see through. Color could be white--brown or a gray color. Amp size will be stamped on the end usually 15 or 20 amps. Should be a few screws around control panel to get it loose.

please follow this steps and fix it. God bless you

Line Fuse


Every microwave oven has a line fuse. This fuse is designed to blow if too much current is drawn through the microwave circuitry. The fuse can be replaced, but the underlying issue should still be investigated and resolved. Otherwise the new fuse will blow also.
Main Control Board


If the microwave is not working the main control board may be defective. This is not common. When a microwave stops working the problem is usually the line fuse or within the high voltage circuit; either the high voltage capacitor, diode, transformer or magnetron.


Thermal Fuse


If the microwave is not working the thermal fuse may have blown. It can be tested for continuity. Watch our fuse testing video for more information.
Thermoprotector


If the microwave is not working the thermoprotector may have tripped. This is a safety device to prevent the microwave from overheating. It can be tested for continuity to see if it's blown.

THE HIGH VOLTAGE FUSE IS IN A PLASTIC EXTRUSION NEXT TO THE CAPACITOR AND DIODE.
YOU CAN USE 3 OR 4 STRANDS OF THIN WIRE FROM MULTI STRAND 15A MAINS CABLE. SOLDER IT OVER THE BLOWN FUSE. I HAVE DONE THIS 100'S OF TIMES.

no its not a health hazard,but if you don't like the looks,they do make a cavity paint especially for microwave ovens,in either a small brush or spray applicator form

Yess there is a ceramic 20 amp 250 volt fuse inside the cabinet. Safety first!!! Unplug the microwave from the wall outlet.

If you remove the four T20 Torx screws that hold the case on(back of cabinet around the edges) and carefully slide the case back and up you can access the fuse. It will be on the circuit board near where the power cord enters. If you have a ohmeter you can check the fuse. The ceramic fuses are not clear so you cant tell a blown fuse by looking.

blown fuse take outer casing off and replace the blown fuse.
You can use a piece of tin foil around the fuse until you are able to replace the fuse.

Yes. The white inside the glass that you are describing is a blown fuse. To find out what size fuse it is look around the base or top of the fuse. You will see engraved something like "125V 5A. You can pick these up at Home Depot or Lowes in the electrical isle. You can also type www.google.com and enter the word "fuse" and then the size it is. (125V 5A) If you have found this information at all helpfull, please rate my solution. Thanks D. Lange

open by unscrewing screws on back and along left side bottom. this lets you swing up the cabinet showing the electrics. the red power line going to the timer is held in place by a metal wire holder that is riveted to the base. wire has a white sleeve between its insulation and the metal wire holder. slide wire and sleeve out to the side of the holder. slide sleeve to side along wire, revealing fuse. need a solder iron and an electronic parts store to get replacement fuse and solder it in. reassemble.


the fuse is a resistor that blows when unit is getting hot. use lower resistance fuse or just hardwire the power line straight through, no fuse, but watch for overheating (not likely) and maybe use breaker outlet

In my case I found an additional fuse, a high tension fuse (5KV 0.8A) in a white on-line isolation slave next to the transformer.
The fuse was blown.
I guess replacing it should solve the problem.

The fuse will be a white or gray ceramic fuse, and you really can't tell if it's blown without actually measuring it. If a new fuse blows when you hit START, you probably have a shorted high voltage capacitor. If you have replaced the fuse and still have no display, then it sounds like there's a problem on the control board. The control board has a built-in surge protector which can short (and smoke) and when it does, it will cut the power to the control board, but not blow the fuse. We repair these nationwide for only $39.95 postpaid. If you or a friend want to check it out or send the control unit in for serivce, we have *critical* safety and disassembly info at our site, which is linked at our listing here on FixYa: http://tinyurl.com/yzjozk