The unit at times would make a grinding type of noise like something was binding. Now the oven does not work at all. Model number is JVM1790SK01 ser # MM901025K mfg July 2007 The microwave turn table was also slow down at times. We mostly use the convection function of the oven. Less than 200 cooking hrs on the unit.

Probably the circulation fan that needs lubricating.
https://www.geapplianceparts.com/store/parts/ModelSectionParts/JVM1790SK01/5/0/0/0/INTERIOR_PARTS_(1)

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see for the turn table obstacle of any screw or something else.

If that grinding noise sounds a little like gargling into a coffee cup, that's a defective magnetron.

You can download GE owner's manuals and installation instructions here.

You can find helpful exploded view diagrams and order parts by entering your full model number from the tag on the oven here.

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It's normal for the motor to turn both ways, that's because of how the motor is made. As for the grinding noise, there's no reason the motor itself would make more noise turning one direction than in the other. The noise might be coming from the roller ring under the glass turntable. One of its wheels might be binding when it tries to turn counterclockwise.

Here's a test. Take the glass tray and roller ring out of the oven. Put a microwave-safe container with a cup or so of water in the oven and start it. Stop the oven and start it again, and the motor should turn the other way. If not, repeat this until you've seen the plastic coupling turn both directions. Note whether you still hear the noise as the motor turns each way. If you do, then there is something wrong with the motor and it should be replaced. If not, the noise is coming from the roller.

In either case, if the oven is truly only a month old it's still under warranty. Since you are concerned about the noise and are worried that the oven is defective, contact the store where you purchased it and see if they will exchange it or take it in for service. If the store can't help you, refer to the owner's manual for the service procedure to follow.

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Those model numbers are not correct. That's likely why you're having trouble.

For model number JVM1790SK01, the part number is WB49X10114.

That's available here.

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Chances are you have a bad stirrer motor or the stirrer blade is jamming or loose on the motor shaft.

Your owner's manual should tell you how to remove the stirrer cover to check it.

If for some reason you don't have your owner's manual, you can download it free here, as well as the parts manual for your model.

You can also 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.

The turntable system consists of the motor, the coupler, the turntable support with rollers, and the tray.

You can see and hear a video of how a turntable motor should sound when you rotate it by hand.

If yours won't rotate or it sounds like it's grinding, etc., you may have a bad motor or plastic coupler.

To replace either, you need to unplug power, then remove the bottom cover of the oven.

You can usually find exploded views and order parts by entering your model number at the Sears parts site.

A full Sears/Kenmore model number has 3 digits, a dot, then 8 more digits, such as ###.########

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It sounds like the knob may be stripped.

What usually happens is the part of the knob that grips the shaft breaks.

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.

That model number doesn't ring a bell. Is that right? Is it foreign?

Chances are the coupler and/or turntable support will be damaged or warped.

Also on some brands, the "packing" (often a rubber grommet) must be replaced.

It will need a new turntable motor. If you or a friend decide to work on it, we have *critical* safety, disassembly, and troubleshooting info at our site, which is linked at our listing here on FixYa: http://tinyurl.com/yzjozk You can find helpful exploded view diagrams and order parts by entering your base model number (without the suffix) here: http://tinyurl.com/gv383