3. TROUBLE ANALYSIS
3.1 Trouble Analysis Procedure
FDD trouble may occur in any of the following nine forms.
(1) Index detection failure
(2) Not ready
(3) Track 0 undetectable
(4) No seek
(5) No write
(6) No read
(7) Read error
(8) IN USE LED won't light
(9) Write protect undetectableCAUTION:
Be sure to switch power off before removing an FDD or PCB from the operating system.
3.1 TROUBLE ANALYSIS TABLE
Item |
Trouble |
No. |
Cause |
JU-3X2, 252A, 253A |
1 |
Index Detection Failure 1
|
1 |
DD motor control PCB |
Replace DD motor assembly |
2 |
DD motor faulty |
Replace DD motor assembly |
||
3 |
Index LED faulty |
Replace | ||
4 | Index detector faulty | Replace | ||
5 | PCB motor ON circuit | Repair | ||
6 | PCB index detection circuit | Repair | ||
2 | Not ready | 1 | See Item 1 | Repair |
2 | PCB ready circuit | Repair | ||
3 | Track 0 detection failure | 1 | Track 00 assembly | Replace |
2 | PCB track 0 detection failure | Repair | ||
4 | No seek | 1 | Stepper motor | Replace |
2 | Guide shaft contamination or damaged | Replace | ||
3 | PCB stepper driver circuit | Repair | ||
5 | No WRITE | 1 | See Item 1 | |
2 | Head disconnected | Replace | ||
3 | Head shorted | Replace | ||
4 | PCB write circuit | Repair | ||
6 | No READ | 1 | See Item 1 | |
2 | See Item 5 | |||
3 | PCB read circuit | Repair | ||
7 | READ ERROR | 1 | See Item 1 | |
2 | See Item 6 | |||
3 | Alignment | Adjust | ||
4 | Azimuth | Unadjustable | ||
5 | Burst | Unadjustable | ||
6 | Asymmetry | |||
7 | Limiter | Adjust | ||
8 | Flag 0 | Adjust | ||
9 | Index period | Replace DD motor assembly | ||
10 | PCB read circuit | Repair | ||
8 | IN USE LED won't light | 1 | LED part | Replace |
2 | PCB IN USE circuit | Repair | ||
9 | Write protect failure | 1 | Write protect part | Replace |
2 | Write protect circuit | Repair |
4
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