Why won’t the turntable turn?

First thing I'd do is check to see if you have power to the turntable motor. Note that microwave ovens have hazardous voltages inside and running the microwave with the cover off can be dangerous without taking the proper electrical hazard precautions.

That being said, the label on the turntable motor says it takes 21V AC, so that should be present when the microwave is running. I can't tell you how to access the motor, but here's a picture from the Appliance Parts Pros website.

GE WB26X10233 Turntable Motor (AP4484245) - AppliancePartsPros.com

Here's the information that you'll be interested in.

=== Description ===

This is a turntable motor intended for use with microwave ovens. A turntable motor is required to rotate the turntable so that food is heated evenly. With time, because of misuse, or as a result of accidental damage, the turntable motor may malfunction or fail. To continue using the appliance efficiently, the turntable motor must be replaced.The primary indication that there is something wrong with the turntable motor is a tray that doesn't spin. When replacing the turntable motor, it is essential to disconnect the machine from the power source. Wear gloves for safety. The part can be replaced easily by removing screws from the back and side of the microwave, which allows the panel to swing open. Take the wires of the old motor and reconnect them to the new one.This turntable motor is an authentic OEM replacement part. It is sold as an individual unit. The turntable motor is made of high-quality, durable materials. The component comes sourced directly from the manufacturer. The replacement part can be installed in several models of microwaves. It is compatible with appliances produced by General Electric, RCA, and Hotpoint brand appliances.

This part fixes the following symptoms

• Tray won't turn

If the 21VAC is present but the motor isn't turning, then you almost certainly need a new motor. If not, we'll have to try and locate a wiring diagram so we can figure out where the most likely point of failure is.

Does the microwave still heat and do everything else correctly?