JMC8100ADB Jenn Air Microwave Fuse Blows

[ALANE2020]

Model Number

JMC8100ADB

Brand

Jenn-Air

Age

More than 10 years

Fuse blows and replacement blows as well.

 

[Jake]

The problem is possibly the door switches.

They are #27 #28 #29 here:

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Unfortunately, they have been discontinued.

Jake

 

[ALANE2020]

Thanks Jake! I will search for replacement, if possible.

 

[ALANE2020]

Tested all 3 switches and they all are working. Now what?

 

[Jake]

Ok, I'll see if Rick can help you, he is much better than I am at Microwaves.

Jake

 

[rickgburton]

Tested all 3 switches and they all are working. Now what?

You need to test the door switches for continuity by opening and closing the door. The monitor interlock is a "deadman" switch that shorts L1 and N together when the door is open. When does the fuse blow? Is it as soon as you plug it in or when you try to use it?

 

[Jake]

Thanks Rick!

Jake

 

[rickgburton]

Anytime!

 

[ALANE2020]

You need to test the door switches for continuity by opening and closing the door. The monitor interlock is a "deadman" switch that shorts L1 and N together when the door is open. When does the fuse blow? Is it as soon as you plug it in or when you try to use it?

Hi Rick-
I removed the plastic switch holder for the 3 and checked the 3 switches with a meter. Top and bottom are the same and when switch is engaged, it shows open. The middle one shows open and when engaged, it shows closed. When fuse is replaced, the inside light and keypad are lit. When I try to start microwave, it makes a quick buzz and goes dead and blows fuse. Any idea what's going on?

 

[rickgburton]

I removed the plastic switch holder for the 3 and checked the 3 switches with a meter.

You need to test the door switches for continuity by opening and closing the door.

Don't remove the switches or the switch holder. Remove the wires on the switches. Connect your meter to the switch and open the door. The switch state should change.

it makes a quick buzz and goes dead and blows fuse.

Remove the two wires on the primary side of the transformer and tape the ends. Start the microwave and see if it still blows the fuse. If the microwave continues to work the short is the high voltage side of the machine.

 

[ALANE2020]

Don't remove the switches or the switch holder. Remove the wires on the switches. Connect your meter to the switch and open the door. The switch state should change.


Remove the two wires on the primary side of the transformer and tape the ends. Start the microwave and see if it still blows the fuse. If the microwave continues to work the short is the high voltage side of the machine.

Thanks! I put the switches back in and they all test ok with door open/close. Do I take 2 wires off the capacitor side of transformer or side sword control panel?

 

[ALANE2020]

* toward not sword

 

[ALANE2020]

Then what if it blows fuse after testing?

 

[rickgburton]

The two wires that supply 110 VAC to the PRIMARY side of the transformer.

Then what if it blows fuse after testing?

The problem is on the low side of the transformer, door switch, control board, etc; etc.

 

[ALANE2020]

It did trip after pulling 2 primary, taping up and started microwave. This is a built in oven that I want to keep for a year or so until get new appliances. Any way of making the fix?
the 3 door switches are good so now what can be done?

 

[rickgburton]

The problem is with the control board. Unfortunately it's been discontinued and no longer available.

 

[ALANE2020]

Bummer! Thanks for your help.

 

[rickgburton]

Anytime!