Panasonic JU-455-5

5.3 Write Error
If an error occurs dur ing write operation, it is usually detected during the next revoluti on by performing a read opera·
ti on called wri te check. To correct an error , write again and r epeat a write check operation. If the result is unsatis-
factory after ten or more write operations, perform a read oper ation on an other tr ack to determine whether it is the
diskette or the dr ive that is wrong. If an error persists , replace the d isk ette and repeat the above procedure.
If th e error still persists, consider the dr i ve defect iv e. If the error is corrected , dispose of the di skette as defective.
5.4 Read Error
Most read errors are soft errors. Da ta can be re covered by fo ll owing the recovery procedure me nt ioned in 5.2.
5.5 Seek Error
(1) Stepper motor or stepper motor dr i ve cir cuit 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 to read the 10 field, check the track number on whi ch 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 m en tioned below:
(1) Head mi salignment: Refer to (Adjustments and Confirmation I tem 9.5)
(2) Head o utp ut too low: Refer to (A djustments and COnfi rmation Item 9.3)
(3) Motor speed difference: Refer to (A djus tments and Confirmation Item 9.1)
6. TROUBLE ANALYSIS
To determ ine the cause of troub le whether it lies in th e FDD , diskette, or contro ller, replace the disk and FDD wi th
good ones. If the FDD is assumed faulty as a re sult, follow the proce dur e below.
6.1 Trouble Analy sis Procedure
FDD troub le may occur in any of the following ten forms.
(1 ) Index detection failure
(2) Not ready
(3 ) Track 0 unde te cta ble
(4) No seek
(5) No write
(6 ) No read
(7) Read err or
(8) IN U SE LED won 't light.
(9) Write protect undetectable
(10) No head load 15.25 ·inch FDD with opt ional head loader)
Check
with the tro ubleshooting flowchart in 6.2.
CAUTION:
Be s ur e to s witch power off before r emoving an FOO or PCB from th e op era ting svnem.
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