Seek Speed Adjustment - NEC D2246 Maintenance Manual

5.3 SEEK SPEED ADJUSTMENT
Follow these steps to adjust the seek speed circuit.
1. Turn on power to the drive and wait until the RDY LED lights.
2. Trigger the oscilloscope at TPI-5.
3. Perform a repeat seek operation between cylinder 000 and cylinder 691, using
either the diagnostic panel (see Appendix C) or the procedure described in
Section 3.6.
4. Observe the waveform at TP7.
5. Adjust potentiometer RVI to achieve a seek start to on-cylinder time of 41 to 43
milliseconds (see Figure 5-3).
6. Check that the voltage at TP3 measures approximately 1.0 volts.
7. Check that the transient response waveform matches the waveform shown in
Figure 5-4.
GND (OV)
3ms-1
3msi
GND (OV)
Figure 5-4 Transient Response Waveform
The following adjustment procedures require a diagnostic panel.
8. Perform an increment seek (see Table C-5) from cylinder 000 to cylinder 691.
9. Check that the oscilloscope waveform matches the waveform in Figure 5-5.
10. Repeat the increment seek for two or more sequences, and verify that there are
no seek errors.
5-3