Write Effo R; Read Error; Seek. Effor; Compatibility Error - Panasonic JU-455-5 Service Manual

5.3 Write Error
If an error
occurs during write operation, it is usually detected during the next revolution by performing a read opera·
tion called write check. To correct an error, write again and repeat a write check operation. If the result is unsatis-
factory after te n or more w rite operations, perform a read operation on another track to determine whether it is the
diskette o r the drive that is wrong . If an error persists , replace the diskette and repeat the above procedure.
If the error still persists, consider the drive defective. If the error is corrected, dispose of the diskette as defective.
5.4 Read Error
Most read errors are soft errors. Da ta can be recovered by foll owing the recovery procedure mentioned in
5.2.
5.5 Seek Error
( 1) Stepper motor or stepper motor drive circuit is faulty .
(2) Faulty ca rriage
There are two ways of seek error recovery. One is to recalibrate to track
00,
and seek back to the original track.
The other is t o read the
10
field, check the track number on which the head is located, and move the head away
from it. And read it again.
5.6 Compatibility Error
The data which is written by one drive may not
be
read by another. Th is error is called a compatibility error, which
can be c.,used mOitly by the fonowing . The check points are ., Iso mentioned below:
(1)
Head misalignment: Refer to (Adjustments a nd Confirmation Item 9.5)
(2)
Head outp ut too low: Refer to (Adjustments and COnfirmation Item
9.3)
(3)
Motor speed difference: Refer to (Adjustments and Confirmation Item
9.1)
6. TROUBLE ANALYSIS
To determ ine the cause of trouble whether it lies in the FDD, diskette, or controller, replace the d isk and FDD with
good ones. If the FDD is assumed faulty as a resu lt, follow the procedure below.
6.1 Trouble Analysis Procedure
FDD trouble may occur in any of the following te n 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 undetectable
(10) No head load 15.25 ·inch FDD with optional head loader)
Check with the tro ubleshooting flowchart in
6.2.
CAUTION :
Be sure to switch power off before removing an FOO or PCB from the operating svnem.
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