Diagnostics and Maintenance
6.3Operation Check
6.3.1Initial seek operation check
If an error is detected during initialization by the initial seek operation check routine at
For an explanation of the operation check before the initial seek, refer to the Section 5.5.
6.3.2Operation 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 MCU on the PCA. The MCU 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.
6.3.3Diagnostic 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.
|