I have a blown internal fuse on my JennAir M170b microwave. The fuse holder says 250V, 15A fuse, but the fuse that was in there is a 125V, 15A fuse. The micro plugs into a normal 110V circuit. Which type of fuse should I use?

If the internal thermal fuse is blown then you need a new oven.

Yes you can,

Most tv repair shops carry them, or appliance repair shops, and Radio Shack.

Yes, if it will fit in the holder tightly... you can always change a low voltage with a higher voltage but never take out a 250 and install a 125...

heatman101

There is usually a 125V, 20 AMP line fuse inside the microwave, mounted at the point where the power cord enters the back of the unit. Or, on a line filter control power. Unfortunately, you will need to uninstall the oven (if this is an over the range model), UNPLUG it and remove the exterior case to access. The case comes off in various ways depending on manufacture and model. Since you provided no model number, I can only give this basic advice.

If the line fuse is blown, you can usually purchase a box of fuses at a hardware store for just a little more than what the manufacturer charges for a single fuse. 125V, 20AMP Ceramic Slow Blow fuses are recommended.

If you have any questions, or need additional assistance troubleshooting, please post back with your MODEL NUMBER and let me know. I hope you find this information helpful.

NOTE: Make sure you take any resistance readings with the microwave UNPLUGGED and the component under test isolated (removed) from the circuit. These ovens can blow a fuse by simply sitting idle. This can occur from any power fluctuations, brown outs, voltage spikes, etc. Or, it could be the symptom of a component that may have failed. If you find the internal fuse blown and replace it, only to have it blow again, you have a more significant problem than a simple blown fuse.

There is usually a 125V, 20 AMP line fuse inside the microwave, mounted at the point where the power cord enters the back of the unit. Unfortunately, you will need to uninstall the oven (if this is an over the range model), UNPLUG it and remove the exterior case to access. The case comes off in various ways depending on manufacture and model. If the model number you listed this question under is correct, the line fuse is connected in line with the power cord inside the unit and is listed as part of item 4 in the parts listing (part number STD384200).

If the line fuse is blown, you can usually purchase a box of fuses at a hardware store for just a little more than what the manufacturer charges for a single fuse. 125V, 20AMP Ceramic Slow Blow fuses are recommended.

If you have any questions, or need additional assistance troubleshooting, please post back and let me know. I hope you find this information helpful.

NOTE: Make sure you take any resistance readings with the microwave UNPLUGGED and the component under test isolated (removed) from the circuit. These ovens can blow a fuse by simply sitting idle. This can occur from any power fluctuations, brown outs, voltage spikes, etc. Or, it could be the symptom of a component that may have failed. If you find the internal fuse blown and replace it, only to have it blow again, you have a more significant problem than a simple blown fuse.

You used to be able to just go to your local Radio Shack and pick one up... Now you'll probably have to try a hardware store, or maybe WalMart.

the hv diode or hv cap or the magnetron are shorted and need replacing

HELLO I BELEIVE THAT YOU HAVE A BLOWN FUSE, OPEN THE MICROWAVE AND LOOK FOR A WHITE FUSE, NORMALLY IS ABOUT 250V/15A TRY TO GET THE SAME ONE AT RADIO SHACK

GOOD LUCK

[email protected]

There should be a paper tag near the fuse holder, or the fuse holder itself should be marked as to current requirement.

Most older or smaller models used 15A or sometimes 12A ceramic fuses.

Newer or more powerful models use 15A or 20A ceramic fuses.

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