Russ R for Model Number JVM1790SK01 Wife was defrosting with the MW and she turned on the over the range light and the entire unit went out. No lights, no panel. I unplugged it and checked the breaker and it hadn't tripped. Checked continuity on the light and fuse and they were good but I replaced them anyway. Still no response. I took the control board off and the key panel. The wiring diagram inside the unit said to check for continuity on the end of the ribbon connector between the key panel and the smart board. I do not have continuity using any combination of the terminals (1 thought 11) on that ribbon connector.
Answer Russ, On the key panel test you will test specific terminals on the harness based on the chart and will have to push the key in order to get continuity. If this test is still not showing any continuity then the keypad would be the issue for buttons not working but would not cause the display to be dead. You will want to test the thermal cutoffs that are on the unit for continuity. Read More... Answered by AppliancePartsPros.com | Monday, September 12, 2016