1. Check F93 on Rotor Board
2. Check F7 on AMX1A3
3. Check for 60 Hz phase 1 signal at anode of CR53 and 60 Hz phase 2 signal at anode of CR66 on Rotor Board
4. Bad Rotor Board
5. Bad CPU Board
6. Check Rotor/Stator Cable
7. Bad CR179 on Filament/kVp Board