(g) Use two channels of oscilloscope.
Connect the 1st channel to the
head load command signal and the 2nd channel to TP9 or TP10 on the
PCBA MFD control.
Triggering is done by the head load command.
Oscilloscope range,
The 1st channel: DC mode, 2V,, 10msec
The 2nd channel: AC mode, 0.5V, 10msec
Note: For example, when you execute the head loading using a DRIVE
SELECT signals it is required to set DS (one of 0 through 3), HS,
and SM straps on.
For the purpose of check and adjustment in this item, it is not
proper to execute the head loading by the MOTOR ON signal with HM
and SM straps on.
Use either of the DRIVE SELECT signal or the
IN
_
USE/HEAD LOAD signal.
(See the Specification item 1-12-3).
(h) Select the side 1 head.
(i) Execute head loading
(j) Execute 2F write operation for one rotation of the disk (250KHz of
WRITE DATA frequency for F D - 5 5 A - F , 5'00KHz for FD-55G) .
(k> Unload the head*
(L) Repeat the head loading and unloading alternately (tapping operation)
and observe the waveform of TP9 or TP10 by the oscilloscope.
(See Fig.418).
(m) Set the oscilloscope trigger to the positive mode and observe the read
waveform at TP9 or TP10 after the input of an unload command.
Confirm
that there is no big spike noise (excludes a small one) or there is
not a continuous unload level (excludes the noise level) as shown
by dotted line in Fig.418.
4050
Summary of Contents for FD-55 Series
Page 7: ...SECTION 3 THEORY OF OPERATION 300...
Page 8: ...3 1 CONSTRUCTION AND FUNCTION 3 1 1 General Block Diagram Fig 301 General block diagram 301...
Page 23: ...Fig 308 Control circuit block diagram 316...
Page 40: ...SECTION 4 MAINTENANCE 4000...
Page 56: ...J4 J12 Option J9 J5 Top view of the FDD Fig 401 Types of connectors 4016...
Page 95: ...Note Refer to item 4 2 1 as to handling of the set screw 4057...
Page 102: ...k Key in Cl SET TMAX L Confirm as in item j 4064...
Page 104: ...Notch B position TP6 voltage 0 5V Max LED indicator Fig 422 Check of file protect sensor 4066...
Page 125: ...k Eject the level disk and release the Invert and ADD modes of the oscilloscope 4087...
Page 136: ...Fig 431 Adjustment track alignment 4098...
Page 153: ...Fig 436 Adjustment of index sensor 4115...
Page 172: ...Fig 440 Replacement of head pad 4134...
Page 176: ...Plate Fig 441 CSS Ass y and shift lever position 4138...
Page 177: ...SECTION 5 DRAWINGS PARTS LIST 500...
Page 179: ...r Fig 501 External view No l 502...
Page 181: ...PCBA DD motor servo Fig 503 External view No 3...
Page 182: ...Fig 504 External view No 4 505...
Page 183: ...Partis nrnnber of the FDD Fig 505 Extemal view No 5 506...
Page 188: ...Fig 506 Mechanical section break down 511...
Page 199: ...PCBA DD MOTOR SERVO PARTS LOCATION Type S i 522A...
Page 200: ...PCBA DD TOR SERVO PARTS LOCATION Type TO 522B...
Page 201: ...PCBA DD MOTOR SERVO PARTS LOCATION Type G 522C...
Page 202: ...PCBA DD MOTOR SERVO PARTS LOCATION Type T 522D...
Page 204: ...523B PCBA DO MOTOR SERVO SCHEMATIC Type K...
Page 205: ...o 523C i 1 PACB DD HOTOR SERVO SCHEMATIC Type G...
Page 206: ...CV 5 3 3 H 2SV 523D PC DD M o t o r SERVO SCHEMATIC Type T...
Page 207: ...PCBA MFD CONTROL B PARTS LOCATION PCB ISSUE A G 524A...
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Page 209: ...PCBA FRONT OPT PARTS LOCATION 525 PO I...
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