Output Modulation Verification; Resolution Verification; Radial Alignment Verification And Adjustment - Panasonic JU-475-4 Service Manual

9.4

Output Modulation Verification

M odulation is calculated by the fo llo w in g formula.
** * | .
Modulation = ---------------------- x 1 0 0 (% )
Using the value obtained in section 9.3, and check th a t the calculated value meets the
specifications o f Table 8.1.
.............t t t t t t u T ............. T
#
9.5

Resolution Verification

(1) Leave the oscilloscope in the same condition as mentioned in section 9.3.
(2) Resolution is calculated by the fo llo w in g formula.
Resolution =
(3) Check th a t the calculated value meets the specifications o f Table 8-1.
9.6 Radial Alignm ent Verification and Adjustment
Introduction
This adjustm ent is normally not necessary.
If the m ounting screws fo r the stepper m otor loosen, or if parts become defective, or if a
co m patibility error occurs, check and readjust according to the fo llo w in g procedure.
Steps(4) to (9) below should be perform ed regardless o f the type, CE or DAD alignm ent diskette
used. Use an alignm ent diskette suitable to the type o f FDD to be adjusted according to Table 3-1.
(1) Insert Panasonic alignm ent diskette.
CAUTION:
Be sure to leave the alignm ent diske tte under room co nd itio n s fo r 20 m inutes before
adjustm ent.
(2) Step to the track specified in the radial alignm ent column o f Table 8-1.
(3) Leave the oscilloscope in the same condition as mentioned in section 9.3.
• Cats Eye System
(4) Check the outp ut waveforms fo r sides 0 and 1. They should appear as in Fig. 9-2.
(5) The tw o waveforms should appear in the am plitude ratio in the radial alignm ent column o f
Table 8-1 or better.
(6) If the specified ratio is not satisfied, loosen the tw o m ounting screws fo r the stepper motor.
Vmax - Vmin „«n/n/x
Vmax + Vmjn
Fig. 9-1
average x1 0 0 (% )
V2F
V1F average
M M axim um voltaqe Value: Vm ax
M inim um Voltage Value: Vmax
: U U U
M odulation