Microwave shows E7 and the turntable does not rotate, though the unit may still heat.

How to Fix / Troubleshooting

Safety: Unplug the microwave before working underneath or inside the cabinet.

Simple checks:

Remove the glass tray and roller ring. Clean both thoroughly and check for broken or missing wheels.
Inspect the turntable coupler (the plastic piece that fits into the tray). Ensure it is not cracked or stripped and that it sits firmly on the motor shaft.
With the tray removed, start a short cycle and observe the coupler through the window (if safe to do so). If it does not turn, stop the cycle and unplug the unit.

Motor access:

Remove the microwave from service and place it on a stable surface.
Remove the bottom panel (if accessible) to expose the turntable motor.
Check the motor wiring connectors for secure attachment.
Test the motor for continuity with a multimeter; an open reading indicates a failed motor.
Replace the motor if defective, reinstall the bottom panel, and test with the tray and roller ring in place.

Note: If the motor tests good but E7 persists, the control board's motor drive circuit may be faulty.