Trouble Shooting: Machine down on anode rotation

The symptom is that as soon as you've pressed the TARGET ON button on the X-RAY panel, the anode rotates only for a fraction of a second and stops.

The most likely cause is a bad or misplaced anode rotation sensor, as shown in the figure. It is probably placed either too close to or too far from the belt pulley. Compare it with the other machine that is running (hopefully the two machines aren't down the same time), and reposition it.