2009 Toyota Corolla won't reverse

I drive 2009 toyota corolla 1.8. the car do not reverse even when the lever is put in R. The auto mechanic replaced the reverse lever inside the gear. Yet the problem persists. He now said that the brain box inside the gear has damaged. is this true? kindly advise urgently.

The problem might be with the neutral safety switch/range sensor.

https://www.rockauto.com/en/catalog/toyota,2009,corolla,1.8l+l4,1442416,electrical-switch+&+relay,neutral+safety+switch+/+range+sensor,4584

This switch tells the computer what gear is selected so the computer can operate the solenoid for that gear.

Tester