IBM 7133 Series, Service Manual

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Chapter 2. Problem Determination Procedures
Problem determination procedures are provided by power-on self-tests (POSTs), service
request numbers, and maintenance analysis procedures (MAPs). Some of these
| procedures use the service aids that are described in the chapter about SSA service aids
| in the SSA Adapters: User’s Guide and Maintenance Information manual. Included in that
| chapter are the service aid error codes.
Disk Drive Module Power-On Self-Tests (POSTs)
The disk drive module POSTs start each time the module is turned on, or when a Send
Diagnostic command is received from the SSA adapter. They check whether the disk
drive module is working correctly. The POSTs also help verify a repair after a FRU has
been exchanged.
The tests are POST-1 and POST-2.
POST-1 runs immediately after the ‘power-on reset’ line goes inactive, and before the disk
drive module motor starts. POST-1 includes tests of:
Microprocessor
ROM
Safety circuits.
If POST-1 completes successfully, POST-2 is enabled.
If POST-1 fails, the disk drive module Check light stays on, and the disk drive module is
not configured into the SSA network.
POST-2 runs after the disk drive module motor has started. POST-2 includes tests of:
Motor control
Servo control
Read and write on the diagnostic cylinder (repeated for all heads)
Error checking and correction (ECC).
If POST-2 completes successfully, the disk drive module is ready for use with the system.
Installing SSA Extensions to Stand-Alone Diagnostics
Attention: This section is relevant only if the using system has AIX Version 3.2.5
installed. AIX Versions 4.1.3 and above already contain the SSA extensions to
stand-alone diagnostics.
Diagnostics and service aids for the SSA subsystem are not included in level 2.4.3 of the
stand-alone diagnostic package. These additional diagnostics and service aids (SSA
extensions) are supplied on a supplemental diagnostic diskette. To install the SSA
extensions:
Chapter 2. Problem Determination Procedures
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