IBM RS/6000 SSA Problem Determination Procedures, Disk Drive Module Power-On Self-Tests POSTs

Chapter 10. SSA Problem Determination Procedures

Problem determination procedures are provided by power-on self-tests service request numbers (SRNs), and maintenance analysis procedures ( Some of these procedures use the using system service aids that “Introduction to Service Aids” on page 7-3.

Disk Drive Module Power-On Self-Tests (POSTs)

Attention: Disk drive modules are fragile. Handle them with care. Follo ESD-sensitive (electro-static discharge) parts procedures when handling modules. For ESD information, see “Handling Static-Sensitive Devices” on

The

disk drive

module

POSTs

start

each time

the

module

is

switched

Send Diagnostic

command

is

received

from the SSA adapter. They check

the

disk

drive

module

is working

correctly. The

POSTs

also

help verif

a 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

disk

drive

module motor

starts. POST-1 includes

tests

of

the:

ŸMicroprocessor

ŸROM

ŸSafety circuits

If POST-1 completes successfully, POST-2 is enabled.

If POST-1 fails,	the	disk	drive	module	check	light	stays on, and	t
is not configured	into	the	SSA network.
POST-2 runs after	the	disk	drive	module	motor	has	started. POST-2	incl
of:

ŸMotor control

ŸServo control

Ÿ Read and write on the diagnostic cylinder (repeated for all h

ŸError checking and correction (ECC)

If POST-2 completes successfully, the disk drive module is ready f using system.

Chapter 10. SSA Problem Determination Procedures10-1