GE Microwave (JE1860SB002) Makes Noise with Smell

[BayouDude]

My GE microwave (JE1860SB 002) made a cracking sound and stopped working.  After some research, I removed the cover and checked the fuse and it was good. I then checked the thermal flame/sensor and discovered it was burned out. I replaced the thermal flame/sensor and now the unit comes on but makes a loud humming sound and has a burnt smell. The next step (according to my research) is checking the diode (cable) which is attached to the capacitor. It appears I need to discharge the capacitor before proceeding? --- BEFORE replacing the sensor, the unit had been unplugged for over one week….AFTER replacing the sensor, the unit was plugged in for about 5 minutes on Jan 25, 2018.

-          What is the best/safest way to discharge the capacitor?  Is an insulated screw driver or pliers needed or will a rubber handle tool work considering the time it has been unplugged?

-          Should I remove the two connecting wires and diode before attempting to discharge the capacitor?

-          If the diode is bad should I still check the Magnetron?

-          If the diode is good, what is the next item to check/test?

[KaveMan]

So you can discharge the capacitor by just shorting an insulated screw driver across both terminals. (Make sure the unit is unplugged!). If it's been unplugged a week , the cap is probably discharged, but it doesn't hurt to be safe. I found there's three things that can cause a smell...a blown diode and the high voltage transformer going bad and the magnetron. Look for signs around the primary windings of the transformer of over heating. I've also seen the mag antenna burnt...you have to remove it from its cradle and physically check it.  If it's bad, replace the diode along with it: cheap money.

Edited January 30, 2018 by KaveMan

[BayouDude]

Thanks for your reply. Where can I find an insulated screw driver?  Home Deport & Lowes doesn't sell them - (the unit has been unplugged for four days).... Also, should I remove it from the unit before discharging any power that may be left in it..... FYI, the thermostat flame/sensor (https://www.geapplianceparts.com/store/parts/spec/WB24X26575?SpecType=SpecType) is called "thermal cut-off" or "thermal fuse" on many other units.  If that gives you a better idea of the source of the problem since it blew, please advise.

[AccApp]

29 minutes ago, BayouDude said:

Thanks for your reply. Where can I find an insulated screw driver?  Home Deport & Lowes doesn't sell them - 

Did you look in the tool section in the electrical aisles?

[moish]

ANY screwdriver will work as long as the handle has no cracks/defects.  Save your money.

[KaveMan]

Moish nailed it...cap doesn't need to be disconnected. Again, a defective mag could cause this issue. You sure  no one had something metal in oven when cooking? How long was it programmed for when it blew?

Edited January 30, 2018 by KaveMan

[BayouDude]

6 hours ago, AccApp said:

Did you look in the tool section in the electrical aisles?

Yes, I checked what they had in the electrical department.  None said insulated and they all said do not cut live wire.  Obviously, the unit is unplugged but the "insulated" tools I've seen online are marked as "insulated" on the packaging.. Both stores sold them online only.

[BayouDude]

6 hours ago, moish said:

ANY screwdriver will work as long as the handle has no cracks/defects.  Save your money.

Thank you. That is my thinking since it has been unplugged for four days.....It is ok to remove the wires before discharging, right? The repair clinic video that I viewed discharged the capacitor (with pliers) and then removed the connections. I don't know how meaningful that is. 

[BayouDude]

1 hour ago, KaveMan said:

Moish nailed it...cap doesn't need to be disconnected. Again, a defective mag could cause this issue. You sure  no one had something metal in oven when cooking? How long was it programmed for when it blew?

There was nothing metal in it when it sparked and shut off. It was on for about 10 seconds (or less) before it stopped....If the diode checks out the mag the next thing to check.  If there is something else I should do, please advise.

[darren412]

Hello Bayoudude     1) I'm assuming you already have looked up your parts breakdown for this counter top microwave to find out if the parts are even available for this model.  Your microwave's Transformer is NLA and subs out to a (ERP part #  ER 10QBP1006 ) I would not recommend putting in a generic high voltage magnetron that would cost you around $100 . Plus what other parts you may have already bought.  The high voltage transformer is also NLA.   The diode is available and the capacitor is available also.  If you do enough of your research on line you can find out how to test all 4 high voltage components.  With that said If your doing this to sharpen your repairing skills Then I understand why your enquiring and asking questions about the high voltage parts. Kudos for you finding the bad heat fuse first.  Usually in my experience with GE microwaves its usually been the High voltage magnetron that causes the issue you are describing. Transformers rarely go but they do fail.  When I have changed Magnetrons I will automatically change the diode with the magnetron.  Capacitors are generally made to be self bleeding on their own so they will automatically discharge BUT THATS NOT ALWAYS THE CASE  so you want to for safety reasons to always shut off power first then discharge capacitor first when your ever checking the microwave for any repair no matter what. I discharge capacitors with a long pair of needle nose pliers that have a rubber insulated handle and touch both sides of the capacitor terminals at the same time to discharge them. Be prepared for a little spark if one occurs  nothing to worry about. You just don't want to be surprised and then jump and you hurt yourself or break something because you were surprised from the spark.  If this project is not to help hone your skills I would suggest you just replace it. You can find another GE compatible microwave for the counter for between $150 - $250 .    Without knowing and checking the high voltage components for their proper operation then I would say , according to what you are explaining for the issues I would replace the Diode first since its available, low cost and easy to replace.  The burning smell is most likely coming from the magnetron if your not smelling residual smoke from the bad thermostat you found .  If it is the magnetron you most likely have no heat either. Again search the web and this site for how to check  the 4 high voltage components on a microwave. Then you will know which part you will want to replace .  The process to check the 4 high voltage components are out there on the web because when I first started looking at microwaves I found out how through the web and this site.