Tip & How-To about Microwave Ovens

How to check the High Voltage transformer in a microwave.

When your microwave is dead, you have checked the fuse and it is ok along with the power to the unit, and the control panel is dead, you probably have a bad transformer. It is the large device behind the control panel which has a laminated core. It will be hooked to the mains and supply power to various circuits.

Remove the power and the cover. Remove at least one wire from each side of the transformer. Check with a DMM for resistance. The primary, side hooked to the mains, should have continuity and low resistance, probably only several ohms. The secondary should have higer resistance but probably less than 100 ohms. If this checks out you need to see my tip at http://www.fixya.com/support/r4223574-microwave_oven_will_not_heat . Do not try to check the secondary under power as it will be at several thousand volts and is dangerous unless you are properly trained to do this!

If the transformer checks bad you can get a new one at a good price at http://www.repairclinic.com.


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