(5) T P 5 (Read data)
Test point to observe the read data pulse.
The signal level at this TP is opposite to that of the READ DATA output
signal.
(Fig.317) Typical waveform of T P 5
Fig.317 shows the waveform at TP5 in normal data read operation.
In the FM method, 2F and IF intervals are observed, while 2 F ,
4/3F,
and
IF intervals are observed in the MFM method.
-
Items
FD-55A
a
,
p
FD-55G
-
2F interval
4y s , Norn.
2ys, Nom.
4/3F interval
6ys, Nom.
3ys, Nom.
IF interval
8y s , Norn.
4ys, Nom.
Pulse width
l±0.5ys
0,5±0.25ys
-
(Table 304) Read data pulse timing
(6 )
TP6 (File protect sensor) -
-
-
-
-
.
•
Test points to observe the output of the file protect detection photo
transistor.
The signal level at this TP is opposite to that of the WRITE PROTECT
output signal.
When a disk with the masked write protect notch (write
327 -
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...
Page 208: ......
Page 209: ...PCBA FRONT OPT PARTS LOCATION 525 PO I...
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