I have a 10 year old MH7130XE Whirlpool microwave oven. The oven and key pad both work, and the oven heats just fine. The problem is the oven begins running as soon as you open the door...without pushing the start button. It will stop when you shut the door.

Well, you probably need a new microwave, or you need to replace the heating element or source.

If everything else is working fine, the magnetron is the likely problem, "heats food and is the heart of the microwave oven" if more than five years old cheaper to replace the whole item.

Hi,
Here is a tip that will help you to figure out what is wrong with yourMicrowave Oven....

Microwave Oven Basic Troubleshooting Tips

heatman101

The volume is written on the front page of your manual. There is no imediate record on line as it is not a current model anymore.

hello,

what this means is partial contact problem from the internal wire from the power supply.

however, what you need to do tofix up your oven back to live i to unscrew your your oven from the luck key (stroll) and then trace down the wire to the element i.e heat provider and the fan to see which wire has gone wrong .

please before you can carry out this function you will have to disconnect any form of power supply on the oven.

thank you and thanks for using fixya.

Hi,
Here is a tip that will help you to figure out what is wrong with yourMicrowave Oven....

Microwave Oven Basic Troubleshooting Tips

heatman101
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The turntable motor may be bad, if you've confirmed the switch is working. The motor is located under the bottom of the microwave and has the shaft penetrating through the bottom of the oven cavity with a drive coupler attached. The coupler is what drives the glass carousel tray. The motor can be accessed by unplugging the microwave and removing the bottom panel screws. The motor is held in by a couple of screws and two connecting wires. The coupler will lift up and pull off the motor shaft from inside the oven.

You can view this part and exploded view diagrams of your microwave at appliancepartspros.com. Just type in your model number and look under the "Magnetron and Air Flow" heading for item 6 (part number AP 3119645).

If you have any questions, please let me know. I hope this helps you.

if everything works except the heating, it is most likely the mag tube is on its way out.........that is the most common reason for it not too cook.......since the microwave is a GE and it is 3.5 years old, i would say you are better off buying a new microwave, the mag tube starts at around $70.00 and up + the labor it costs too have a service person put it in........around another $60.00

Did you replace the fuse yet?

Did the new one blow?

If so, and if it went dead almost immediately after pressing the Start pad, that's usually a shorted high-voltage capacitor.

If so, and if if it went dead a few seconds after pressing the Start pad, that's usually a failing high-voltage transformer.

If the new one did not blow, and the microwave still makes a growling or grinding noise, but does not heat, you probably have a shorted high voltage diode or a bad magnetron.

Here are some links you or someone you know can use (in order given) for test help, but read the safety warnings first:

http://www.gallawa.com/microtech/diode.html (if it is NOT shorted, it's probably fine)
http://www.gallawa.com/microtech/cap_test.html
http://www.gallawa.com/microtech/mag_test.html
http://www.gallawa.com/microtech/xformer.html

There should also be a "mini-manual" hidden inside the unit behind the control panel or hidden on the left side behind the grille, which is very helpful when troubleshooting & testing.

You can usually find helpful exploded view diagrams and order parts by entering your full model number here.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.