Tighe
Well-known member
I have a Whirlpool over the range microwave that I have had for about a year and a half and it has stopped heating.
I checked the voltage to the transformer and it is getting 120v like it should, so that means that the problem is with one of the following:
High Voltage Capacitor
High Voltage Diode
Transformer
Magnetron
I am using the instructions in the service sheet inside the microwave to test each of the components.
Transformer:
I believe that the transformer is correct as I am getting the proper resistance on both ends, although I have never seen a transformer with 3 leads on the output side.
Magnetron
I made a mistake when I first started looking at this, I disconnected the leads and forgot which goes where. The case has FA and F on opposite sides of each terminal on the magnetron but I don't know what that means. Are magnetrons polaric? I would think so based on that they run on DC or Pulsed current. One terminal is the filment can anyone help me figure out which is which? I think that it is fine though.
HV Diode
This is pretty much impossible to test with my craftsman meter, both ways read 1 ohm (is that infinite?) If I use a 9v battery I get 6v one way and 2v the other way. I am thinking it might be bad?
HV Capacitor
This I am supposed to set the meter to the Rx1000 scale (I did 2000 as there is no 1000 scale on my meter). Normal for terminal to terminal is momentarily indicates several ohms, gradually returns to infinite. Terminal to case is supposed to be infinite resistance. I get 1 ohm reading both ways, same as if the probes were not touching anything.
A replacement HV capacitor is $55 so I don't want to toss out money like that if it won't fix it. Also, if I don't figure out the proper polarity for the magnetron I will be afraid to power it up as I will probably fry it in the process and waste $55 plus shipping.
I checked the voltage to the transformer and it is getting 120v like it should, so that means that the problem is with one of the following:
High Voltage Capacitor
High Voltage Diode
Transformer
Magnetron
I am using the instructions in the service sheet inside the microwave to test each of the components.
Transformer:
I believe that the transformer is correct as I am getting the proper resistance on both ends, although I have never seen a transformer with 3 leads on the output side.
Magnetron
I made a mistake when I first started looking at this, I disconnected the leads and forgot which goes where. The case has FA and F on opposite sides of each terminal on the magnetron but I don't know what that means. Are magnetrons polaric? I would think so based on that they run on DC or Pulsed current. One terminal is the filment can anyone help me figure out which is which? I think that it is fine though.
HV Diode
This is pretty much impossible to test with my craftsman meter, both ways read 1 ohm (is that infinite?) If I use a 9v battery I get 6v one way and 2v the other way. I am thinking it might be bad?
HV Capacitor
This I am supposed to set the meter to the Rx1000 scale (I did 2000 as there is no 1000 scale on my meter). Normal for terminal to terminal is momentarily indicates several ohms, gradually returns to infinite. Terminal to case is supposed to be infinite resistance. I get 1 ohm reading both ways, same as if the probes were not touching anything.
A replacement HV capacitor is $55 so I don't want to toss out money like that if it won't fix it. Also, if I don't figure out the proper polarity for the magnetron I will be afraid to power it up as I will probably fry it in the process and waste $55 plus shipping.
