• ** REMEMBER! **The microwave can still shock you even unplugged!!

    ALWAYS discharge the high-voltage capacitor first if you even think your hands will come close to any HIGH VOLTAGE components.

    Jeff mentions this: Anything in the high voltage ( magnetron, capacitor, diode, wires to and from ):
    ...Use a metal ( not the shiny chrome type ) screw driver with a insulated handle to short across ( touch both at the same time ) the terminals of the high voltage capacitor to discharge it.

    From Jeff's site: http://www.applianceaid.com/component-testing.php

    Jake

Maytag MMV5207 blowing hvt fuse, not heating

Chuey_316

Premium Member
Joined
Feb 11, 2017
Messages
2
Location
USA
Model Number
MMV5207
Brand
Maytag
Age
1-5 years
As the title states the microwave is not heating, and if I replace the hvt fuse and start the microwave it will hum loudly and blow again. I've replaced the magnetron, and I've verified that the diode and capacitor are good by putting them in another unit, and it ran fine.

I've tested the door switches as well. The top and bottom ones have continuity while closed, and not while open. The middle switch was the opposite, but with the connector plugged in it has continuity both opened and closed.

Unsure of what to check next.
 

Chuey_316

Premium Member
Joined
Feb 11, 2017
Messages
2
Location
USA
Just want to add that I am getting 120 to the low side of the transformer until the fuse pops. It does the same thing with the mag unplugged. Also, after the fuse pops, the buzzing stops.
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
102,080
Location
McMullen Valley, Arizona
Hi,

We need the complete model number, MMV5207 is just the partial model number.

The model number tag should be inside the door.

Jake
 

hugo1969

Premium Member
Joined
Mar 20, 2017
Messages
6
Location
California
Hi all,

I have a very similar issue on my Jenn-Air microwave model: JMV8208BA

The HV 20A fuse keeps blowing as soon as the start button is pressed, have checked all the door switches and appear to be good.

After disconnecting the capacitor, diode and magnetron, the fuse still blows. The only time the fuse does not blow is if the primary side of the transformer is not connected.
The white cable on the secondary side of the transformer measures under 5 ohms to ground. There is no physical damage to the transformer but it seems that is a low resistance measurement.

Hugo
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
102,080
Location
McMullen Valley, Arizona
Hi Hugo,

I'll see if Rick can assist you on this, him and Jeff are experts on microwaves.

Can you please post your complete model number? You missing a digit or two at the end. The model number tag should be inside the door.

Here's the results I get: 12 models matched: JMV8208BA

Jake
 

hugo1969

Premium Member
Joined
Mar 20, 2017
Messages
6
Location
California
Hi Jake,

Unfortunately the label inside the door is no longer legible. The manual has JMV8208BA/BC. The schematic also has the BA number.
 

rickgburton

Appliance Tech - Moderator
Staff member
Joined
Jul 11, 2006
Messages
34,672
Location
Murray, Utah 84107, United States
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