Jump to content


Use this Search Box to Find Appliance Repair Help Now
Need help finding your model number?
365-day return policy on all parts purchased here, even electrical parts that have been installed!


FAQs | Store | Memberships | Repair Videos | Academy | Newsletter | Beer Fund | Contact


Welcome to Appliantology.org, the Web's Premiere Appliance Repair Resource for DIYers!

The world-famous Samurai Appliance Repair Forums


You can post a question and get repair help for FREE! Click here to get started.


Already a member of the Appliantology Academy? Just sign in with your username and password in the upper right-hand corner of the screen.

 






Troubleshooting a microwave oven using the Divide and Conquer Method

Posted by Samurai Appliance Repair Man, in Microwave Oven 26 February 2012 · 1,668 views

microwave oven
Electrically speaking, microwave ovens have two sections: low voltage and high voltage. The low voltage section consists of the door switches, start button, control panel, turntable motor, cooling fan, stirrer motor, and some miscellaneous switches. The high voltage section consists of the transformer (which steps 120vac line voltage in residential units and 240vac in some commercial units up to 2,000+ volts), the high voltage rectifier (diode), and the charging capacitor (which together with the rectifier doubles the output of the HV transformer), and the star of the show, the magnetron. You can see pictures of all these parts and where they're located in typical microwave ovens in these spiffy, interactive diagrams:

Detailed Countertop Microwave Oven Diagram

Detailed Built-in Microwave Oven Diagram

Lots of times, when you're troubleshooting a microwave problem, it's helpful to figure out early on whether the problem is in the low voltage section or the high voltage section because this narrows the problem down considerably. Professional Appliantologists call this the Divide and Conquer Method of Troubleshooting and it is a very powerful technique indeed. At this point, I'll turn it over to Academy Fellow Budget Appliance Repair (Willie), Professor Emeritus of Appliantology, to explain this sublime troubleshooting kata:

One way to test this is to remove the ?black (L1) power wire from the high voltage transformer, or both wires going to the the primary 110 volt side of the high voltage transformer if you can't figure out which is the line and which is neutral, (be sure to tape them safely away from touching anything).

Then turn the microwave on and it should startup and count down and cooling fan should run, just won't do any heating, (by disconnecting the high voltage transformer you have completely eliminated the high voltage system from the picture). If this works OK then you know the switches and complete control circuit is OK.

If the test with the high voltage system disabled above works, next reconnect the transformer and disconnect the two wires going to the mag tube, (make sure to mark the terminals they come off of), and make sure they are safely away from everything and give it another try. If again it works without blowing the fuse you can be pretty sure you have a bad mag tube, even if it doesn't show as a directly shorted mag tube when checking continuity from the terminals to the mag tube case.


After you've applied the Divide and Conquer Method to figure out what's wrong with your microwave oven, you can buy the parts with a 365-day return policy here ==> http://www.repaircli...rts?RCAID=24038


Source: GE Spacesaver JVM1441BH04 Microwave continually blows fuse after slamming door




Like - Plus - Connect - View

Facebook-icon50x50.png google-plus-icon-50x50.png YouTube-icon50x50.png

Find Parts & Diagrams Here

Looking for Appliance Parts? Enter your model number, part number, or even a part description and find it here. 365-day return policy on all parts purchased here, even electrical parts that have been installed!

Search My Blog

Latest Visitors

Random Album Image

Happy New Year 2012!

23 user(s) viewing

0 members, 23 guests, 0 anonymous users


FAQs | Store | Memberships | Repair Videos | Academy | Newsletter | Beer Fund | Contact


Use the Appliantology Parts Finder to Get What You Need!
Enter a model number, part number, type of appliance, brand, or even a part description.
365-day return policy on all parts purchased here, even electrical parts that have been installed!

Your Sometimes-Lucid Host:
Samurai Appliance Repair Man
"If I can't help you fix your appliance and make you 100% satisfied, I will come to your home and slice open my belly,
spilling my steaming entrails onto your floor."

The Appliance Guru | AppliancePartsResource.com | Samurai's Blog

Real Time Analytics