Kenmore Elite Micorwave

[Handywithtools]

No Power to a Kenmore Elite Microwave- Model 665.61882101.
 
I replace the AC input fuse and it restored power but when runninig the popcorn setting as a test it blew the fuse again half way through the cycle.  Prior to the main fuse blowing the output on certain settings was very low- popcorn needed to be run twice to get the same outcome as a "normal" operation under that setting.
 
It is a nice unit but is it worth fixing?  I would like to keep it depending on parts needed.
 
Thanks for any suggestions on what could be wrong with it.

[tgoods]

The closest model I can find to that number is 665.61682101. I bet it's a bad inverter board, W10217710. It's what regulates power to the magnetron so that could explain the low power.  It doesn't seem like a dead short because it doesn't blow the fuse right away.

[Handywithtools]

Sorry typo on the model- 665.61682101.
 
Thanks for the correction, response and suggestion.  When looking at the suggested troubleshooting tips within the unit (wiring diagram) is just said to inspect the board.  Is there anything else I should do to test the board?  How about verifying the condtion of the magentron?
 
 
 
 

[tgoods]

To test the mag, check for filament resistance between the terminals, should be less than 1Ω. Check for resistance from the terminals to ground, should be infinite. I suppose it could be the mag, but probably not.  I've only seen them either work or not, never seen a weak one.  Most bad mags I've seen have passed the resistance tests even though they are bad and shorted mags will buzz loudly. If you have a clamp-on ammeter, clamp it to the main power wire and check your amp draw.  It's probably drawing a little over the fuse rating.  Check your AC voltage while it's running. Stay away from the high voltage side of the inverter, that voltage is deadly.  If everything checks out, I still think it's the inverter board.

[Handywithtools]

Thanks for the information. 
 
I did the ohm test on the mag per the wiring diagrams troubleshooting tips and it passed.  I will pull the invertor board and look to see any glaring failed parts on the board.
 
I do not have clamp ammeter and I am giving the high voltage the respect it deserves. The unit is unplugged when being serviced due to my limited knowledge of micorwave but along with my knowledge of other electrical appliances regarding High Voltage!
 
Once again thanks for the response.
 
 
 
 
 

[whjeffs]

I almost always change the inverter & the magnetron at the same time on any of the inverter type microwaves. Too many times in the past I would end up with a recall after just changing the inverter board because it was a mag beginning to fail that caused the problem with the inverter in the first place.

[krazytech]

Check the diodes on the board for continuity .should only have continuity one way... the way the arrow is pointing...

[RegUS_PatOff]

run away ! 
Whirlpool Kenmore 665.61682101 inverter M/W made by Panasonic 

[eakint]

To test the mag, check for filament resistance between the terminals, should be less than 1Ω. Check for resistance from the terminals to ground, should be infinite. I suppose it could be the mag, but probably not.  I've only seen them either work or not, never seen a weak one.  Most bad mags I've seen have passed the resistance tests even though they are bad and shorted mags will buzz loudly. If you have a clamp-on ammeter, clamp it to the main power wire and check your amp draw.  It's probably drawing a little over the fuse rating.  Check your AC voltage while it's running. Stay away from the high voltage side of the inverter, that voltage is deadly.  If everything checks out, I still think it's the inverter board.

Hi, I also had a recent failure with a Kenmore elite microwave/ultrawave "speedcook".  I have done the obvious checking of connectors to the inverter board, nothing burnt or funny looking.  the magnetron passed it resistance test.  However, I did notive one thing before tearing it all apart.  I had it sitting on the counter with the top/side one piece shroud off and I heard it an electrical buzz (not zap, but pulsing buzz-zzz for 1-2 seconds every 5-6 seconds or so)  then after 2-3 times of that it would spit out error code F7.  With behavior like that i was suspecting the magnetron was done, but wasn't sure???  what is the next step in diagnosis?  thanks.
-todd

[whjeffs]

Hi, I also had a recent failure with a Kenmore elite microwave/ultrawave "speedcook".  I have done the obvious checking of connectors to the inverter board, nothing burnt or funny looking.  the magnetron passed it resistance test.  However, I did notive one thing before tearing it all apart.  I had it sitting on the counter with the top/side one piece shroud off and I heard it an electrical buzz (not zap, but pulsing buzz-zzz for 1-2 seconds every 5-6 seconds or so)  then after 2-3 times of that it would spit out error code F7.  With behavior like that i was suspecting the magnetron was done, but wasn't sure???  what is the next step in diagnosis?  thanks.
-todd

Best thing to do in this scenario is replace the magnetron and the inverter board. Even though a mag passes a resistance check it can still be bad and a bad mag puts a lot of stress on the inverter board. Years ago I used to try to just replace one or the other but 99% of the time I ended up having to replace the other part as well.

[eakint]

Best thing to do in this scenario is replace the magnetron and the inverter board. Even though a mag passes a resistance check it can still be bad and a bad mag puts a lot of stress on the inverter board. Years ago I used to try to just replace one or the other but 99% of the time I ended up having to replace the other part as well.

Thanks, I would typcially troubleshoot a component at a time.  sure cannot find anything else suspect, connections, caps, diodes, etc.  how can I test the invertor board (it is a little hard to get to on this microwave / halogen speedcook model # 665.63793302 )  you can see in the pics I have the magnetron out, but the invertor board is really buried under some layers...  any tips on testing and removal for that one?

thanks,
-todd

[whjeffs]

Basically all you can test is that the inverter is getting 120 volts to the gray & red wires when heating. Then you can check amp draw while it is heating, should be around 11 amps. My experience though with these tells me every time replace the magnetron AND inverter board together. The fact that you get a pulsing buzz along with the F7 indicates one of those components is bad. Too many times I have replaced just the inverter board, only to have the new inverter board ruined by a bad magnetron that otherwise tested "good". If you were going to try to replace only one part at a time, I would replace the magnetron first, as a bad inverter is not likely to damage a new magnetron. However, if you replace the magnetron and it works, don't expect the inverter to last long anyway as they usually don't after a bad magnetron has stressed them.