Sometimes after a cooking program is completed and the microwave has turned off, we open the microwave door, and the fan and turntable come on as if it’s cooking again. I assume it’s not actually cooking, but I could be wrong. It doesn’t happen all the time, but it seems to be getting more frequent.
You need to check for a “sticky” door switch or door switch mounting bracket,
If the switch is left activated by one of the problems mentioned, ity will power up either or both the fan and turntable since they’re on the same circuit.
Good Luck,
Thanks a ton Joe.
I’ll try a little cleanup and lube and see if that does it. If not, I’ll get the parts ordered up.
Is it safe to assume the microwave is not “cooking” when it comes on like this? From your comments, it sounds like it’s just the fan and turntable coming on, correct?
Thanks again.
[quote=barberd;300602]Thanks a ton Joe.
I’ll try a little cleanup and lube and see if that does it. If not, I’ll get the parts ordered up.
Is it safe to assume the microwave is not “cooking” when it comes on like this? From your comments, it sounds like it’s just the fan and turntable coming on, correct?
Thanks again.[/quote]
Yes,
I’m 99.9% sure, just the light and turntable are active, in this situation.
Be careful when you’re reaching inside the unit, there’s a lot of high voltage wires and components in there.
Good Luck,
Seems that a little cleanup and lube didn’t do the trick. Worked for a few more days and now a new problem that may be the same parts. Now when we start the microwave, the light comes on and the timer runs, but the fan doesn’t come on and it doesn’t cook anything. Is this related to the same switches? If so, should i replace the Primary, Secondary and Monitor Switches, or just Primary/Secondary? I’d just hate to replace all the switches and find out that the magetron has gone out, or something else significant.
Thanks!!
[quote=barberd;304486]Seems that a little cleanup and lube didn’t do the trick. Worked for a few more days and now a new problem that may be the same parts. Now when we start the microwave, the light comes on and the timer runs, but the fan doesn’t come on and it doesn’t cook anything. Is this related to the same switches? If so, should i replace the Primary, Secondary and Monitor Switches, or just Primary/Secondary? I’d just hate to replace all the switches and find out that the magetron has gone out, or something else significant.
Thanks!![/quote]
Barberd,
I’m still pretty sure, you’ve got a bad primary door switch or door switch mount assembly.
Here are the door switch circuits for testing.
[LEFT]Primary, Secondary, and Monitor Interlock Switch Checkout Procedure
Switch Check By Door Open Door Closed[SIZE=1][FONT=HelveticaNeue-Bold][/LEFT]
[LEFT][/FONT][/SIZE]Primary[FONT=HelveticaNeue-Roman][SIZE=1]
Interlock[/LEFT]
[/SIZE][/FONT]1. [FONT=HelveticaNeue-Bold][SIZE=1]
[LEFT][/SIZE][/FONT]Unplug microwave oven or disconnect power.
2.
[/LEFT]
[FONT=HelveticaNeue-Bold][SIZE=1]
[LEFT][/SIZE][/FONT]Disconnect the wires at the Primary Interlock Switch.
3.
[/LEFT]
[FONT=HelveticaNeue-Bold][SIZE=1]
[/SIZE][/FONT]Check the terminals.
Door open - Door closed +
[SIZE=1][FONT=HelveticaNeue-Roman][LEFT]Secondary
[LEFT]Interlock
[/FONT][/SIZE]1. [/LEFT]
[/LEFT]
[FONT=HelveticaNeue-Bold][SIZE=1]
[LEFT][/SIZE][/FONT]Unplug microwave oven or disconnect power.
2.
[/LEFT]
[FONT=HelveticaNeue-Bold][SIZE=1]
[LEFT][/SIZE][/FONT]Disconnect pin connector at the electronic control.
3.
[/LEFT]
[FONT=HelveticaNeue-Bold][SIZE=1]
[/SIZE][/FONT]Check from the green wire (pin 7) to the pink wire
[SIZE=1][FONT=HelveticaNeue-Roman][LEFT](pin 8).
Door open - Door closed +
[LEFT]Monitor
Interlock
[/FONT][/SIZE]1. [/LEFT]
[/LEFT]
[FONT=HelveticaNeue-Bold][SIZE=1]
[LEFT][/SIZE][/FONT]Unplug microwave oven or disconnect power.
2.
[/LEFT]
[FONT=HelveticaNeue-Bold][SIZE=1]
[/SIZE][/FONT]Disconnect the common terminal (yellow wire) and the
[SIZE=1][FONT=HelveticaNeue-Roman][LEFT]normally closed terminal (brown wire).
[/FONT][/SIZE]3. [FONT=HelveticaNeue-Bold][SIZE=1]
[/SIZE][/FONT]
[/LEFT]
[FONT=HelveticaNeue-Bold][SIZE=1]
[/SIZE][/FONT]Check the terminals.
[SIZE=1][FONT=HelveticaNeue-Roman][LEFT]Door open + Door closed -
FONT=HelveticaNeue-Roman Continuity (-) No Continuity[/FONT]
You should also check, the No. 1 relay on the printed circuit control board.
Disconnect the 8 pin connector on the board
Check across pin #3 and pin #4 for an open circuit, in the no power mode.
If the relay has a closed circuit in the no power mode, you’ve got a bad control board.
I doubt, you’ve got a high voltage side problem at this point.
Good Luck,
[/FONT][/SIZE]
[/LEFT]
Thanks Joe.
Replaced the Primary and Secondary switches and it seems to be working fine now. Great price on the switches here at Appliance Parts Pros by the way.
[quote=barberd;308626]Thanks Joe.
Replaced the Primary and Secondary switches and it seems to be working fine now. Great price on the switches here at Appliance Parts Pros by the way.[/quote]
Barberd,
Great job,
Did you get the mounting bracket screws back on and tight.
We appreciate your satisfaction with the prices and technical assistance.
Glad to have been a help,
Good Luck,
I had the same issue. Light and fan come on when you open the door. They go off again when you close it. Otherwise works as expected.
I checked all three switches and they all worked per the diagnostic guide. I also checked the relay (but my 8-pin connector only had connections on pins 1, 3, 5 and 8, so I think it should be pins 3 and 5 rather than 3 and 4). That showed an open circuit, as expected.
Everything appeared fine, so I put it back together and the problem is no longer happening (at least for a day or two so far). I’ll see if the issue comes back.
Thank you for the great instructions and diagnostic steps!!!
[quote=mself2;815746]I had the same issue. Light and fan come on when you open the door. They go off again when you close it. Otherwise works as expected.
I checked all three switches and they all worked per the diagnostic guide. I also checked the relay (but my 8-pin connector only had connections on pins 1, 3, 5 and 8, so I think it should be pins 3 and 5 rather than 3 and 4). That showed an open circuit, as expected.
Everything appeared fine, so I put it back together and the problem is no longer happening (at least for a day or two so far). I’ll see if the issue comes back.
Thank you for the great instructions and diagnostic steps!!![/quote]
Mself, You’re Welcome !! Glad we could help you out. Keep an eye out on the door switches and bracket, that’s the place to start, if the issue returns.