Sharp microwave is dead

It could be that the magentron has failed. Does it make a loud hum or buzzing noise when you try to use the microwave only function? If it does, chances are that the magnetron has shorted out. The replacement cost can be as high as the cost of a new oven, so it rarely makes sense to fix.

We have the same exact microwave & this happened with ours just last night. I'm wondering the same if it is worth having it fixed.

To allow us to help you effectively (at no charge), please post a NEW problem to FixYa, and please include your brand name and the full model number from the tag in or on the unit, your symptoms ("runs but no heat"), as well as the answers to these questions:

- When you try to microwave are the inside light, internal cooling fan and turntable all working?

- Is there any unusual noise or is it louder or quieter than normal?

(A loud buzz, hum, or groan is usually a shorted high voltage rectifier diode, but a sound like gurgling into an empty coffee mug is one symptom of a failed magnetron, and yet the mag can be bad without that sound.)

We have a sound clip here of what a microwave should sound like when the cooling fan and high voltage section are working.

If it went dead almost immediately after pressing the Start pad, that's usually a shorted high-voltage capacitor.

If it went dead a few seconds after pressing the Start pad, that's usually a failing high-voltage transformer.

If it goes dead or blows the breaker (or GFI) when you plug it in or open or close the door, then there's a problem with a door switch or door switch mount.

If you or someone you know decide to look into it, we have critical safety information and disassembly information at our site, and our link is at our listing here on FixYa.

Here are some links you or someone you know can use (in order given) for test help, but read the safety warnings first:
http://www.gallawa.com/microtech/cap_test.html
http://www.gallawa.com/microtech/diode.html (if it is NOT shorted, it's probably fine)
http://www.gallawa.com/microtech/xformer.html

You can usually find exploded views Sears parts site.

BUT Once you have the part numbers, the best place to order Sharp parts is Tritronics.

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

Most likely a shorted capacitor is causing the fuse to blow. Easy and cheap to fix.
Check with www.martinmicrowave.com or call toll free 1-877-894-0035 for parts info

This is almost certainly a blown high voltage diode.

Please reply back with your brand and model number so we can help you.

Yes that noise is causing your fuse to blow. Machine gun sound sounds like the High Voltage Capacitor or High voltage diode is bad. (Loud humming sound is usually a bad magnetron or bad power transformer). Most of these parts are inexpensive, except for the magnetron. But most of the repair bill is most likely going to be for labor.

Based on your model, it looks like an over the range microwave. And to fix any of these problems require the removal of the microwave from the wall. So its up to you if you want to deal with that hassle. But you also have to consider that you'll probably have a hard time trying to find a new microwave that will fit.

Sounds like you just fried your magnetron. Normally when they go bad, they make a very loud noise like what you described. The smell concerns me because you may have ruined the waveguide as well. If the magnetron burns through the protective painted surface of the waveguide, the waveguide is ruined. In most microwave ovens this means replacing the entire unit because the waveguide is not replaceable. Putting a new magnetron in a damaged waveguide will result in the same arcing and eventual failure. In addition to the magnetron, the following components are part of the same high voltage network: HV Transformer HV Diode HV Capacitor Magnetron Thermal Cut-Out Any one of these components could have also been damaged. I DO NOT recommend taking any voltage measurements inside the HV network. Potentials of over 4000 volts can be reached and make it very dangerous for the do-it-yourselfer. Taking resistance readings with the unit unplugged is strongly encouraged. If you decide to pursue a repair, inspect the magnetron tip and inside of the waveguide first. If the magnetron is melted and/or there are burn marks inside the waveguide, a new microwave may be a in order. This actually may be a better option than an expensive repair. I hope you find this advice helpful.