Operation Check; Initial Seek Operation Check; Operation Test; Diagnostic Test - Fujitsu MAB3091FC Series Maintenance Manual

2.2

Operation Check

2.2.1

Initial seek operation check

If an error is detected during initialization by the initial seek operation check routine at turning
on the Fault LED. The spindle motor of the disk drive then stops, and the disk drive is
unusable.
For an explanation of the operation check before the initial seek, refer to the PRODUCT
Manual.
2.2.2

Operation test

While the host computer is processing data, the IDD monitors disk drive operation including
data processing, command processing, and seek operations. If the IDD detects an error, the
IDD posts the error to the INIT. The INIT then posts the error to the user.
The user may detect an intermittent or nonfatal error such as abnormal noise, abnormal odor,
or very slow operation.
An error posted in an operation test must be investigated. Replace the disk drive to see
whether the error was caused by the disk drive.
Often, errors posted in an operation test may be caused by the host system. Possible causes
include insufficient power capacity, loose cable connection, insufficient timing or insufficient
mechanical play, and problems related to other systems.
If an operation error is detected by the error detection circuit of the disk drive, an interrupt
occurs. The interrupt is posted to the MPU on the PCA. The MPU stops the currently
processed command, and causes the CHECK CONDITION status to post the error to the INIT.
When receiving the CHECK CONDITION status, the INIT issues a REQUEST SENSE
command to collect detailed information about the error. The INIT then issues a REZERO
UNIT command to return the read/write head to track 00. In normal processing, the IDD itself
or INIT determines how to handle the error (processing retry or stop).
To analyze the error posted in the operation test, reconstruct the conditions in which the error
occurred. Then, start troubleshooting the whole host system by replacing the disk drive.
2.2.3

Diagnostic test

The diagnostic test is executed to find a faulty subassembly in a faulty disk drive, or to check
disk drive performance. This test is usually a combination of specific disk drive functions or
group of functions. This test may be executed using a different host computers or test
equipment and away from the environment where the error first occurred.
To analyze the error posted in the diagnostic test, reconstruct the conditions in which the error
occurred. Then, look for a possibly faulty subassembly or part of the disk drive.
The procedures to be used in this test depend largely on the type of test equipment used, and
are not covered by this manual.
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