Recently my GE Spacemaker Microwave (7 years old, model JVM1631BB) stopped heating food. When I start it used to work as if it is heating food, but it was not heating food. After doing some research online I found that it is mostly fault of magnetron tube inside Microwave. And also found that there is extended warranty on that one part for a total of 10 years.This I found in the user manual which I downloaded from GE website (see the link below).

Initially I scheduled service appointment with GE service department. When I started to dig around how much it would cost for GE guys to fix the problem, I found that it would cost me more than $220. Wow !! I was shocked, brand new over the range Microwave can be bought for $150 and above. After some more research over the web I called GE parts department (888-239-6832) they took serial number of the Microwave and were happy to ship me the magnetron tube part. Part arrived within 2 business days.

Now I have part and not sure what it takes to replace the part in Microwave. I have decided take a shot at replacing the part myself, with help from a friend. I am happy to report that we have successfully replaced magnetron tube in the Microwave. It was not easy, it took about 2 hours to take down Microwave, open everything replace it and put it back. If you are not motivated to save some bucks then you should not attempt this.

Here are the steps we took to replace it

Warning: I am not an electrician or repairman, following steps are from my experience. You should be careful while handling capacitor and other parts.

1. Unplug Microwave at least few hours before
2. Remove Microwave from above oven range by somebody holding Microwave from ground unscrew the screws from cabinet
3. Remove top cover of Microwave
4. Make sure to keep screws correctly in a place you remember what goes where
   
5. Make sure capacitor is discharged, GE manual inside Microwave says capacitor will discharge within 30 seconds once it is off. As a precaution check the voltage in capacitor to make sure there is no electricity
   
6. Remove other panels around magnetron part
7. You need to remove lot of connecting wires, should be careful to note down what goes where
   
8. If possible take digital photos to refer back when you put everything back together
   
9. Remove bottom panel and remove transformer (You must remove transformer to be able to remove Magnetron)
   
10. Now it should be easy to remove magnetron
    
11. Replace new magnetron and screw it. We had to put one outside part from old magnetron to new one because new one was missing that. Check to make sure both old and new one are exactly the same
    
12. Make sure put all wires properly back
    
13. Now put transformer back and screw it
    
14. Put capacitor panel in place and screw it
    
15. This might be a good time to test the Microwave to make sure it works fine now
    
16. Now cover the top panels and start to screw everything
17. Once everything assembled put the Microwave back above range put screws from top