no electric power to my microwave


  #1  
Old 02-16-21, 05:47 PM
W
Member
Thread Starter
Join Date: Jul 2011
Location: USA
Posts: 148
Received 0 Votes on 0 Posts
no electric power to my microwave

My microwave is black out, no any function no lights, no power. It happens under below situation: I open the door accidently, when my microwave is heating food, then power is lost. Before, such case happens, and my strip in garage jumped. Under such case, it is relative easy, just push strip back, microwave work again, but not this time.
My microwave is Frigidaire FFMV1645TS.
Is this possible the fuse in microwave broken? How many fuses does my microwave have? How to find it?

Thanks
 
  #2  
Old 02-16-21, 09:03 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 62,053
Received 1,505 Votes on 1,393 Posts
This is a problem fairly common in GE and Frigidaire microwave ovens. There are multiple (3) door switches. Typically two for operation and one is a fail safe. When the microwave is running and you open the door....the operation switches are supposed to shut off the high voltage. With age.... these switches get out of alignment and the microwave keeps running so the fail safe switch dead shorts the circuit. This causes the fuse to blow. You can change the fuse but the problem will not go away and will get worse with age. The unit uses one fuse.
20A ceramic fuses

Microwave ovens are not easy to service and the door switches aren't easy to work on either. Usually what happens is that the plastic housing that holds the switches cracks. Some people have glued it and replaced the door switches. It's not a basic DIY repair and not something I recommend for most people.

The following links cover replacing fuses on generic models. There are others listed.
Fuse replacement videos
 
  #3  
Old 02-17-21, 03:47 AM
M
Member
Join Date: Sep 2019
Location: Canada
Posts: 1,553
Received 163 Votes on 150 Posts
Also try the unit on a different circuit.
 
  #4  
Old 02-17-21, 05:58 PM
W
Member
Thread Starter
Join Date: Jul 2011
Location: USA
Posts: 148
Received 0 Votes on 0 Posts
Thank you very much. I am going to buy a fuse. Is there anything I need to pay the attention?
 
  #5  
Old 02-17-21, 06:03 PM
W
Member
Thread Starter
Join Date: Jul 2011
Location: USA
Posts: 148
Received 0 Votes on 0 Posts
@Manden: How to do to try unit on different circuits and why (circuit problem?)?

Thanks
 
  #6  
Old 02-17-21, 08:01 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 62,053
Received 1,505 Votes on 1,393 Posts
Yes.... you need to pay attention to what you touch inside the microwave oven.
You'll want to replace the fuse with the power cord unplugged.
Touch only the fuse area as the microwave section holds power when unplugged.
 
  #7  
Old 02-17-21, 08:34 PM
Join Date: Jan 2009
Location: United States
Posts: 842
Received 38 Votes on 36 Posts
The fuse is usually right where the power cord comes into the unit also beware you will probably need a Security Bit screw driver set not so tamper proof or security if these are so easy to obtain LoL!
 
  #8  
Old 02-18-21, 03:21 AM
M
Member
Join Date: Sep 2019
Location: Canada
Posts: 1,553
Received 163 Votes on 150 Posts
The unit is dead.
So it could be that it is not getting any power ort that there is a problem with the microwave.
Trying it on a different receptacle is easy to do and will help verify that it is a microwave problem.
 
  #9  
Old 02-19-21, 01:34 PM
W
Member
Thread Starter
Join Date: Jul 2011
Location: USA
Posts: 148
Received 0 Votes on 0 Posts
Lowes here only sale 20A Fast-Acting Glass Tube Fuse (1/4" X 1-1/4", 32Vac, Fuse Voltage 32Vdc) made by Cooper Bussmann, not Ceramic. Can I use this glass tube fuse?
Go to AMAZON, there are Pack of 5-20 Amp Microwave Ceramic Slow Blow Fuse 250V Universal Replace for GE WB27X10388 and Whirlpool, Kenmore Other Microwave Ovens. The cost is ~$5 for 4, can it to replace Frigidiare part 5304509451, which is more expensive (1.125"-0.25"-0.25")?
It looks the voltage is different, 32 and 250, also one is fast acting and another is slow blow, plus one is glass and another one is ceramic which one I should buy?


Thanks
 

Last edited by wen831; 02-19-21 at 02:40 PM.
  #10  
Old 02-19-21, 05:58 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 62,053
Received 1,505 Votes on 1,393 Posts
You have to use a fuse that is rated at least as high as the voltage it's used on.
In other words..... you cannot use a 32v fuse on a 120v circuit.

I only use the ceramic fuses in microwave ovens. The composition quenches the arc better.
 
  #11  
Old 02-19-21, 06:33 PM
Join Date: Jan 2009
Location: United States
Posts: 842
Received 38 Votes on 36 Posts
I don't know if you have Home Depot in your area but they do have those Fuses there.
 
  #12  
Old 02-23-21, 01:16 PM
W
Member
Thread Starter
Join Date: Jul 2011
Location: USA
Posts: 148
Received 0 Votes on 0 Posts
Thanks for FUSE information and I went to Home Depot and bought 20A 250V fuse.
After installed, the fuse blow out again.
As what said in the consultations, it maybe door switch problem? How to check and which one should be replaced?

Thanks
 
  #13  
Old 02-23-21, 04:42 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 62,053
Received 1,505 Votes on 1,393 Posts
Refer back to my original post. You will need to pull the microwave apart. You'll need to get to the door switches. First thing to check is to make sure they're all solidly mounted. You will need a meter to check their operation. If there are 3 switches..... 2 will close/short when the door is closed. The 3rd one will short when the door is opened.

At this point.... since your microwave oven has been routinely shorting.... you may have high voltage/power supply problems. There are videos on you tube that illustrate working on the switches.
 
wen831 voted this post useful.
  #14  
Old 02-26-21, 03:35 PM
W
Member
Thread Starter
Join Date: Jul 2011
Location: USA
Posts: 148
Received 0 Votes on 0 Posts
The job is well done, wish this time could last little longer. Thanks
 
  #15  
Old 02-26-21, 04:03 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 62,053
Received 1,505 Votes on 1,393 Posts
Unfortunately this is a problem that effects many semi inexpensive units.
I've seen many problems with GE units and a lot with Frigidaire.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: