Xerox 8500DN Service Manual - Page 168

General Troubleshooting Rotates the drum at a constant velocity and samples the Y-Axis position. Uses the data to determine Y-Axis motor and drum vibration and the most significant other vibrational frequencies. Y-Axis Geometry R# Definition 0 Drum Normalized FFT Power (none) Typical Value (8400) 1 Drum Frequency (hz) 2 Motor FFT Power Ratio (none) 3 Motor Frequency (hz) 4 FFT Power Ratio 1 (none) 5 Frequency 1 Frequency (hz) 6 FFT Power Ratio 2 (none) 7 Frequency 2 Frequency (hz) Typical Value (8500/ 8550/8560) Actions -3900 to 6000 Reports the normalized FFT power amplitude of the drum frequency. The normalized value is generated by dividing the drum FFT power by 1.0xE13. 1.25 to 7.5 Reports the current drum frequency. -200 to 250 Reports the ration of the FFT power amplitude of the motor frequency to the FFT power amplitude of the drum frequency. 44 to 48 Reports the current motor frequency. -20000 to 25000 Reports the ratio of the FFT power amplitude of the most powerful FFT frequency (not including the drum or motor), to the FFT power amplitude of the drum frequency. 45 to 110 Reports the frequency of the most powerful FFT frequency (not including the drum or motor). -14000 to 17000 Reports the ratio of the FFT power amplitude of the second most powerful FFT frequency (not including the drum or motor), to the FFT power amplitude of the drum frequency. -70 to 140 Reports the frequency of the second most powerful FFT frequency (not including the drum or motor). 4-38 Phaser 8400/8500/8550/8560 Color Printer Service Manual