The location of the locking solenoid is illustrated with the red box.

Confirm that the solenoid is indeed broken by attempting to unlock the robot through Franka Desk UI.

The bronze pin (purple box) should actuate upon unlocking and stay in the "up" position. In a broken solenoid, the pin will not stay up.

The green box shows the "up" position of a functional solenoid. Note that the bronze pin is no longer flush with the lower part of the black cap.

See step 7 of the guide for a video of the nominal unlock behavior.