Panasonic JU-475-4, Service Manual

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9.8 Index Burst Verification and Adjustment
(1) Insert an alignm ent diskette. Seek to the track specified in the index burst column o f Table
8
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1
.
(2) Set the oscilloscope in the same conditions as in section 9.7, and set horizontal deflection to
50ps/ division.
(3) Check th a t th e tim e fro m oscilloscope s ta rt to th e fir s t data meets th e in d ex b urst
specifications o f Table 8-1.
(4) If the specifications are not met, adjust as follows.
• Loosen the index detector m ounting screws enough to free the assembly.
• Adjust the tim in g to meet the specifications o f Table 8-1.
• Retighten the screw.
• Check the tim in g again.
9.9 Track 0 Sensor Adjustment
(1) Set the oscilloscope as follows.
TRIG SYNC CHI CH2 VERT HORIZ
INT i l l ! ! TP12 TP 8
:.............
0.2V 1 ms
(2) Step between specified tracks at in the track 0 item o f Table 8-1. (Turn the seek delay switch
on the exerciser to adjust 3 ms seek.)
(3) Loosen the track 0 sensor screw and adjust until the waveform on the oscilloscope appears as
shown in Fig. 9-6.
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