Sharp microwave drawer not heating. When the diode burns out, it prevents the magnetron from receiving enough voltage to heat. Make sure the diode isn’t burnt out, and replace it if necessary.
For more helpful tips on what you can do should your microwave suddenly stop heating in your Sharp microwave, read this article here.
Sharp microwave drawer not heating
If you’re looking to figure out the cause of your microwave heating arrhythmically or not at all, this guide is the perfect way to get started. Not sure where to begin?
We’ve got you covered with our comprehensive guide detailing common issues and providing tips on how to approach troubleshooting methods.
The diode is located in the high-voltage system and is used to prevent the current from turning around. This prevents energy loss in a system when it is transferring power to a load.
If it fails, the microwave won’t be able to heat food. It can often appear visibly burned out so you should inspect it and if it’s visibly damaged, then replace it.
If no visible evidence of damage is discovered, test with a multimeter or battery that goes into series with the diode (ensure you swap the polarities).
When switched back, there should only be continuity in one way; this allows for the detection of a broken or bad diode by isolating which one does not conduct reversibly.
Magnetron burnt out
The cooking chamber contains a microwave generator, colloquially called a magnetron. The magnetron produces microwaves when it is instructed to by the controller.
The cooking chamber of a microwave oven has the capability of storing enough electricity to shock you. There is an extremely lethal high-voltage capacitor in the cooking chamber that can hold up to 1,000 volts even after the microwave oven has been unplugged from being turned on and off.
Warning: Disassembling this component may be fatal. It should only be replaced with the same or equivalent model of the cooking chamber as instructed by a licensed technician.
The door switches don’t work
There are usually three or four switches on microwaves. They will go over and over again until the microwave stops working. You cannot open or close it if this happens.
It is also where you can find the problem with your microwave oven and you will be able to fix it yourself by going through all of the switches. But make sure it is not very wet outside because we don’t want any problems with our efforts to repair the microwave unit.
The Thermal Fuse is blown
A thermal fuse is what cuts off the microwave if it’s overheating. To find out whether the fuse has already been damaged, use a multimeter to determine if there is continuity in the junction where the fuse is situated.
It’s likely that you will need to replace that equipment if there is no continuity. A damaged thermal fuse cannot be reset, so, therefore, as a precautionary measure to avoid hazards, claim it from your appliance technician and have him/her replace it instead.
A fault may exist in the main control board
There is a possibility that the main control board is faulty. Most of the time, this isn’t the case. Sometimes, a control board is misdiagnosed by homeowners who are replacing parts unnecessarily before replacing a part as a control board.
Make sure to check all of the other components in your microwave which could actually be faulty, especially if you’ve just recently moved into the home or even last year encountered an issue with your microwave (perhaps it would turn on but not heat up).
If all the other components are functioning properly and the model number printed on your board matches those for known faulty models, then the main control board needs to be replaced.
It isn’t always necessary to replace a part only because it malfunctions; sometimes, this happens when we just need another part instead.
The high voltage capacitor needs to be replaced
The microwave transformer is wired to a capacitor and diode, which in turn are connected to the high-voltage wiring. The diode protects the capacitor while the capacitor helps double the voltage supplied to the secondary (oscillating) winding of the transformer.
The capacitor works with the diode, even as it functions to hold extra power when needed under certain circumstances.
To determine if your high-voltage capacitor is performing properly, use a volt-ohm meter (VOM) with testing functionality for capacitors. Alternatively, you can use an electronic circuit tester.
Note that replacing this component should only be attempted by someone knowledgeable in electronics repairs or other similar fields who are equipped with special tools, including safety equipment.
A licensed technician should handle any upgrades, repairs, or replacements related to microwave replacement parts because of their high-voltage electrical components.
If the microwave overheats, the Thermoprotector shuts it off. The microwave won’t heat or start if the thermostat trips.
You will need a multimeter to check for continuity in the thermostat to determine the reason it is tripping. If there are no readings on your multimeter, replace the Thermo protector.