What Caused a Microwave’s Ceramic Fuse to Blow?

November 25, 2019
Microwave Repair

Like most appliances that produce heat, your microwave comes equipped with a ceramic fuse. When the appliance overheats or suffers a dangerous power fluctuation, this fuse will blow to prevent fire or excess damage to the microwave by cutting the power. When your fuse blows, it can easily be replaced near the power cord of your microwave, but it is crucial that you investigate why it happened or you will be replacing a fuse on almost every use.

Causes of a Blown Microwave Fuse

The unfortunate news for owners of a microwave with a blown fuse is that the potential causes of it are quite the list. Generally, something has short-circuited or is overheating. Here are the most common causes of this issue.

  • Power Surge
  • A non-functioning cooling fan that caused overheating
  • Short in the controller
  • Short in the power cord
  • Short in the magnetron
  • Short in the high voltage diode
  • Faulty door interlock switches
  • Misaligned door

What we are trying to say is this issue can be caused by a short in pretty much all of a microwave’s working parts. This makes things somewhat difficult to troubleshoot. Furthermore, as a microwave’s capacitors can hold a lethal charge even when unplugged, it can be dangerous to test things like the high voltage diode without properly discharging them first.

If your microwave’s ceramic fuse keeps blowing and it needs investigation, this is something that is definitely best left to a professional. If you have a microwave or any other appliance that is malfunctioning and you need help getting it fixed up quickly, contact us today to see what Central Valley Appliance can do to help. Microwaves are a small tool, but they are both crucial in the kitchen and dangerous to DIY repair, it is best to just leave them to us.


Leave a Reply