For the microwave to function, power needs to be applied to the control board. It then connects the power via relays to the various components as required.
-
Looking at the wiring diagram. power passes through a line filter (did you test that?) and then on to the L.V. (low voltage) transformer on the control board.
+
Looking at the wiring diagram, power passes through a line filter (did you test that?) and then on to the L.V. (low voltage) transformer on the control board.
For a GFCI to trip means that there was current flow between the active leg and earth when there shouldn’t be, so you may have to also test for that as well (faulty HV transformer?).
-
Here’s a [https://www.repairfaq.org/REPAIR/F_micfaq5.html#MICFAQ_013|link] that may help as it shows how to test most of the functions in a microwave oven.
+
Here’s a [link|https://www.repairfaq.org/REPAIR/F_micfaq5.html#MICFAQ_013|link] that may help as it shows how to test most of the functions in a microwave oven.
'''Be safety aware''' ''when working in a microwave oven. The HV capacitor can store >5000V DC for months even if the power has been disconnected for this length of time.'' This amount of '''voltage can seriously injure you'''. ''The HV capacitor needs to be discharged correctly as soon as possible after removing the cover from the oven and before commencing any other work.''
Hi @abitt ,
For the microwave to function, power needs to be applied to the control board. It then connects the power via relays to the various components as required.
Looking at the wiring diagram. power passes through a line filter (did you test that?) and then on to the L.V. (low voltage) transformer on the control board.
For a GFCI to trip means that there was current flow between the active leg and earth when there shouldn’t be, so you may have to also test for that as well (faulty HV transformer?).
Here’s a [https://www.repairfaq.org/REPAIR/F_micfaq5.html#MICFAQ_013|link] that may help as it shows how to test most of the functions in a microwave oven.
'''Be safety aware''' ''when working in a microwave oven. The HV capacitor can store >5000V DC for months even if the power has been disconnected for this length of time.'' This amount of '''voltage can seriously injure you'''. ''The HV capacitor needs to be discharged correctly as soon as possible after removing the cover from the oven and before commencing any other work.''