Microwave CPR

(and how you can fix a microwave DOA too!)

Not long ago, our microwave decided it was done.  No big light show, no power, no light, no nothing.  It was just done.  My first thought was that it had served us well for 11 years and it was probably time for a new one anyway.  But then again….maybe it wasn’t done after all.  Whenever something with a plug quits working, the fuse is my #1 suspect.  So I decided to take it down and investigate.  (Please note that before attempting ANY repairs you should always, always, ALWAYS unplug the power cord!!)
The first thing I noticed was that I needed a special bit to open up the outer case.  Here’s what the screws looked like:

It’s like a six pointed star with a little circle in the middle.  I don’t know about you, but I don’t normally keep bits like this on hand.  So I made a trip to my local hardware store and found this Bosch 6-Piece Security TORX Bit Set for $8.97.

Once I got them home and took them out of the package, I found the one I needed was a size T20.  There were four of these security screws on the back of the microwave, one in each corner.

I also needed a Phillips head to remove one screw on each side.

Here’s what it looks like with the outer case removed.


See that little off-white-yellowish plastic case looking thing near the top on the right?

Yeah, that one.  That’s where the fuse is housed.  Yours may be a little different, but it should be located near where the power cord comes into the back of the microwave.

Open it up, and there’s the fuse.  It doesn’t look very suspicious, does it?

Take the fuse out of the little silver holders by pulling gently on each end.  Now take a look at the silver caps on the ends of the fuse.  They are your friends here.  They’ll tell you what kind of replacement fuse to get because YOU CANNOT JUST PUT ANY OL’ FUSE BACK IN HERE!!   (Ask me how I know and I’ll tell you about our 200lb paperweight!)  So don’t do it….as tempted as you may be…just leave those other fuses in the toolbox (unless the stars have aligned and you happen to already have the right ones on hand!) and make another trip into town to get the right ones.  Yes, this fix will require two trips because you won’t know what type of fuse you’ll need until you get the back open.  (Incidentally, when I Googled this specific type of fuse, it came up listed as a microwave fuse….maybe microwaves aren’t that different from each other after all).  I didn’t get a picture of it, but the fuse I replaced was stamped with “20A 250V” on one end.  Be sure you get both the amperage and the voltage correct.

After a trip to RadioShack, I had what I needed:  a four-pack for $3.29.  

I like to write what the fuses are for in case I need another one later.  My memory is not that good!

Now put the new fuse inside the little plastic thingy (like my very technical terms?)  Be sure you get the wire connections put back inside the plastic before you snap it shut.  At this point, you may be dying to know if you’ve fixed it or not, but don’t even THINK about plugging it in until you get the cover back on!  Be safe!!

When you put the cover back on, there’s a lip on the inside edge that slides in behind another lip on the outside of the microwave.  Be sure you get those tucked in or your cover won’t go back on properly.

Put all the screws back in, then cross your fingers and plug it in!

If you’re lucky like me, your microwave will reward you and come back to life.  Yay!  I spent less than $15 for a repair that would have cost upwards of 4 times that just for the house call alone.  If I need to do it again, the next repair will be free.  Free is good.

Obviously, your microwave will be a little different than mine (unless it’s a KitchenAid #KCMS145JSS) but maybe this little tutorial will give you that little nudge to give replacing the fuse a try before you call that repairman or make a trip to the appliance store to buy a new one.  Then you can spend that money on something a little more fun.  Like paint.  Or fabric.  :)

If you do decide to take the plunge and try to fix your own, here’s a summary of what you may need:
  • Security Type Torx Bit (mine needed a size T20, but yours might be different)
  • Power drill or screw driver
  • Philips head screw bit
  • Replacement fuse (mine took a Slow Blow 20A/250V Ceramic Fuse)
  • about 10 minutes of time once you’ve gotten all your supplies gathered

You may not need it now, but one morning when you’re trying to reheat that cup of coffee and your microwave refuses to cooperate, you’ll be glad you saw this!  So what do you think?  Are you up for it?  Let me know what your experiences have been with this type of repair.

Thanks for reading!



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