SHARP MODEL #R1470A PLACED PLASTIC BOWL TO MELT BUTTER AND A LOAD POP HAPPED AFTER HITTING START BUTTON. THERE IS NOW A LOAD HUM AND WILL NOT HEAT. THE CONTROL PANEL STILL WORKS

William Miller

• 9179 Answers
• Posted on Mar 30, 2008

SOURCE: my sharp r-510hw flashing like crazy

Quite often this is due to grease or food particles stuck to the inside of the oven or stuck on or behind the waveguide cover.

The waveguide cover is usually about the size of a playing card and often held in place by a plastic rivet.

It can be fragile, and the metal edges of the oven behind it can be sharp, so be careful!

The cover and the metal behind it should be cleaned with a mild, non-ammonia cleaner.

If the cavity metal of the oven is chipped or charred, it will have to be sanded smooth and clean.

Then you can apply some high-temperature appliance paint, available from places like Wal-Mart, Lowe's or Builder's Square.

If your waveguide cover is burned, it will need to be replaced.

You can order Sharp parts from Tritronics at http://www.wehaveparts.com

We're happy to help and we appreciate your thoughtful rating of our answer.

William Miller

• 9179 Answers
• Posted on Nov 29, 2009

SOURCE: I have a Sharp R-308NP Microwave that won't heat anything

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

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.

According to the owner's manual here, the warranty is one year, but the magnetron itself is covered for 5 years.

If it's under warranty, you can find your nearest authorized servicer here.

If it's out of warranty, 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/diode.html
(if it is NOT shorted or burned looking, it's probably fine)

http://www.gallawa.com/microtech/mag_test.html
(continuity can be good even though mag is bad!)

You can order parts for this brand from Encompass here or you can call them toll-free at 866-779-5835.

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

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