IBM RS6000 - 7026 - H70 Service Manual

Also see for RS/6000 7025 F50 Series: User guide Service guide Service guide

Appendix A. SSA Problem Determination ProceduresProblem determination procedures are provided by power-on self-tests (POSTs),service request numbers (SRNs), and maintenance analysis procedures (MAPs).Some of these procedures use the using system service aids that are described in“SSA Service Aids” on page 3-64.Disk Drive Module Power-On Self-Tests (POSTs)Attention: Disk drive modules are fragile. Handle them with care. Follow allESD-sensitive parts procedures when handling disk drive modules. For ESDinformation, see “Handling Static–Sensitive Devices” on page 6-2.The disk drive module POSTs start each time the module is switched on or when aSend Diagnostic command is received from the SSA adapter. They check whetherthe disk drive module is working correctly. The POSTs also help verify a repair aftera FRU has been exchanged.There are two power-on self-tests: POST-1 and POST-2.POST-1 runs immediately after the ‘power-on reset’ line goes inactive, and beforethe disk drive module motor starts. POST-1 includes tests of the: Microprocessor ROM Safety circuitsIf POST-1 completes successfully, POST-2 is enabled.If POST-1 fails, the disk drive module check light stays on, and the disk drive moduleis not configured into the SSA network.POST-2 runs after the disk drive module motor has started. POST-2 includes testsof: 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 by theusing system.Appendix A. SSA Problem Determination Procedures A-1