Tip & How-To about Microwave Ovens

Microwave Oven will not heat.

When your microwave oven has power, the fan runs, carousel turns, light comes on but the unit does not heat up you have a bad high voltage diode, bad filter capacitor or a bad magnatron in that order. The diode and capacitor do not cost very much. You can get them at www.mcmelectroncs.com or www.repairclinic.com . Replacement would mean removing the unit from under the counter (if not a tabletop unit) and removing the case. Locate the diode and capacitor. They should be near the power section behind the transformer and display. The diode is attached to the chassis on one side with a screw and on the other end with a spade lug to one side of the filter capacitor. The diode is brown and has an arrow on the side. The filter capacitor is a large oval silver can with two spade lug connections on one end. After replacing both parts if the unit will not heat you would need a new magnatron. The part is fairly expensive, but depending on the cost of your unit, it may pay to replace it. You should be able to get the magnatron at www.repairclinic.com . The magnatron replacement is not difficult. About four screws and several wires on spade lugs. Just be concientious or mark everything for correct reassembly. Also make sure the part is correctly installed and all seals are in place. You do not want microwave energy to leak out.

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1 Answer

Microwave keypad & light works but the microwave will not come on to heat


Check all fuse inside the unit for open condition, also if your microwave is running but not heating up food then you have an open high voltage Diode, this is a very high power diode that is connected to a High Voltage Capacitor, Caution is due here because of the very high voltage use in theis circuit must be discharged before attempting repairs./

Aug 24, 2011 | Microwave Ovens

1 Answer

microwave runs lights come on but it doesnt heat up any food


It shows that magnetron is not operating,check high voltage diode grounded from the high voltage capacitor by replacing the same with same specification,if problem remains then check connection leads connected with magnetron for loose or corrosion,finally check by replacing the magnetron.

Feb 04, 2011 | Sharp Carousel R530EST Microwave Oven

1 Answer

sharp carousel microwave model # 508ak has power but does not heat food when you press the start button. thanks in advance!


9 times out of 10 this is usually this is a bad magnetron, the other time is sometimes a bad high voltage diode. See components section. Q - My microwave is running and sounds like it is working but will not heat up anything.
A - Many thing can do this but, common things are....loose high voltage wire.....poor solder joint on board.....magnetron.....power relay.....

Q - The microwave display counts down and the inside light is on, but nothing is heating and the fan is not running.
A - This most commonly is a bad door switch, other possible problems are a faulty relay or solder joint on the power module, but a bad door switch is most common.
thanks.

Jul 11, 2009 | Sharp R-510HW Microwave Oven

1 Answer

Microwave will not heat


Q - The microwave makes a loud "hum or buzz" noise but will not heat up the food?
A - 9 times out of 10 this is usually this is a bad magnetron, the other time is sometimes a bad high voltage diode. See components section.
Q - My microwave is running and sounds like it is working but will not heat up anything.
A - Many thing can do this but, common things are....loose high voltage wire.....poor solder joint on board.....magnetron.....power relay.....
 Q - The microwave display counts down and the inside light is on,  but nothing is heating and the fan is not running.
A - This most commonly is a bad door switch, other possible problems are a faulty relay or solder joint on the power module, but a bad door switch is most common.
Q - The fan in my microwave oven is not running will this hurt my microwave?
A - YES, the fan cools the magnetron and electronics, take the microwave in for service, most fans are not too expensive to replace.
Q - My microwave blows the fuse inside itself as soon as I push the start button.
A - Usually a shorted high voltage capacitor...see components section.



Mar 06, 2009 | GE Spacemaker JVM1640SJ Microwave Oven

1 Answer

boiling waer under micro wave lots of steam into micro wave, turn on micro wave ,pop noise like glass miro wave comes on louder hum than normal no heat


Q - The microwave display counts down and the inside light is on,  but nothing is heating and the fan is not running.
A - This most commonly is a bad door switch, other possible problems are a faulty relay or solder joint on the power module, but a bad door switch is most common.
 Q - My microwave is running and sounds like it is working but will not heat up anything.
A - Many thing can do this but, common things are....loose high voltage wire.....poor solder joint on board.....magnetron.....power relay.....
Q - The microwave makes a loud "hum or buzz" noise but will not heat up the food?
A - 9 times out of 10 this is usually this is a bad magnetron, the other time is sometimes a bad high voltage diode. See components section.

Mar 03, 2009 | Amana Radarange Microwave Oven

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