Brad R April 12, 2018 for Model Number JVM1790SK01 Unit not heating. Replaced Magnatron and diode. Did not fix. Check capacitor for continuity between the two plates for a short, no continuity. Checked voltage coming from control panel to transformer, 120 AC. Checked door switches but not sure if all are supposed to be open then closed when the door is closed. Running out of things to test. When I place a glass of water in the microwave and heat for 45 seconds, water still feels cool.
1 Answer Hello Brad. If you have power to the transformer but nothing coming out the HV side, you will need to replace the HV transformer on the unit. Read More...
Ernie January 21, 2017 for Model Number JVM1640WJ02 My microwave had no power so I replaced the top thermostat and now have power but no heat produced. I checked the lower thermostat WB27X11034 for continuity and none. I ordered a new thermostat and out of the bag it has no continuity? Is that a faulty thermo or is it an open circuit? My next move was to check the diode? Thanks
1 Answer Hello Ernie, There is one thermostat in the unit that is normally open so that is not a bad part "out of the bag". You should use the tech sheet to troubleshoot the unit electrically. The tech sheet will show where there should be continuity and where there is none. To check the diode, you will need a dc test meter and a 9 volt battery. Test for 9Vdc with the battery in series with the diode, then reverse the diode in the circuit. With the diode in one direction it should show the 9Vdc and in the other, it should not. Read More...
1 Answer Hello Mickey. You most likely have a "high voltage" side malfunction. Transformer, diode, magnetron, Capacitor. You will need to be extremely careful if you decide to test the components with a multi meter, Very high residual voltage is present, so make sure you remove power to the microwave and short across the terminals on the capacitor. The magnetron should have a reading of less than 1 ohm resistance across the two terminals, and an "open" circuit between each terminal and chassis ground. The diode/rectifier should have a resistance reading in one direction only, no resistance, or resistance in both directions indicate a faulty diode. The primary winding on the trans former should read approximately 450 Ohms resistance, the secondary winding should read 80 ohms resistance, and the filament transformer should read 100 ohms resistance. If all the readings are proper and in range, replace the magnetron. Read More...