- Model Number
- CMV1000ADW
Maytag CMV1000ADW Microwave under cabinet light & fan always on, after bulb replace short circuit
I have a CMV1000ADW over the range microwave that I'm trying to troubleshoot the control board on. Background is that the under cabinet light bulbs were missing and I failed to unplug the microwave before installing new bulbs and inadvertently caused a short circuit. The microwave appeared to be functioning properly other than lack of bulbs before this incident.
I took the control board out and could see that the short circuit had burned a couple of traces on the pcb which I have repaired with jumper splices. I also tested all the capacitors with an ESR meter and replaced all that measured bad. I used a 12V battery to test relays 2, 3, 4, 5, & 6 and verified that all were functioning.
I also checked coil resistance on these same relays and all appear to be within spec tolerances. I checked relay 7 a switching relay and confirmed that it is in the NC position however I have not yet attempted to energize that relay to test for the NO condition. When I reinstalled the board in the microwave the under cabinet lights come on but so does the fan and it is now not possible to turn off either the fan or the under cabinet lights.
I am able to change the speed of the fan between high and low speed but it does not respond to the "off" selection. I currently have the board out of the unit again. Any ideas on what else I should check that is causing this "always on" condition? I did not check door open / door closed condition to see if it had any affect on fan and lights.
I also didn't check to see if turntable was turning and don't recall if internal cabinet light was on or off. The door was closed when I plugged the unit in and observed the fan and under cabinet light "always on" condition. I will upload a copy of the wiring diagram that comes with the unit.
I have a CMV1000ADW over the range microwave that I'm trying to troubleshoot the control board on. Background is that the under cabinet light bulbs were missing and I failed to unplug the microwave before installing new bulbs and inadvertently caused a short circuit. The microwave appeared to be functioning properly other than lack of bulbs before this incident.
I took the control board out and could see that the short circuit had burned a couple of traces on the pcb which I have repaired with jumper splices. I also tested all the capacitors with an ESR meter and replaced all that measured bad. I used a 12V battery to test relays 2, 3, 4, 5, & 6 and verified that all were functioning.
I also checked coil resistance on these same relays and all appear to be within spec tolerances. I checked relay 7 a switching relay and confirmed that it is in the NC position however I have not yet attempted to energize that relay to test for the NO condition. When I reinstalled the board in the microwave the under cabinet lights come on but so does the fan and it is now not possible to turn off either the fan or the under cabinet lights.
I am able to change the speed of the fan between high and low speed but it does not respond to the "off" selection. I currently have the board out of the unit again. Any ideas on what else I should check that is causing this "always on" condition? I did not check door open / door closed condition to see if it had any affect on fan and lights.
I also didn't check to see if turntable was turning and don't recall if internal cabinet light was on or off. The door was closed when I plugged the unit in and observed the fan and under cabinet light "always on" condition. I will upload a copy of the wiring diagram that comes with the unit.