HP 9020 User Manual

3-4 Testing and Troubleshooting
Self-Tests and Diagnostics Overview
Three overlapping levels of diagnostics provide the primary service support tool for the computer.
These are the module self-tests, the self-test supervisory code (STSC), and the system functional
tests. The module self-tests
and STSC are executed at powerup. The system functional tests are
contained
on the System Functional Test Discs which can be loaded by the customer engineer.
Procedures for running module self-tests and STSC are contained in Appendix B. Procedures for
running the System Functional Test are contained
in the System Functional Test User's manual.
A power-up condition or a SCRATCH
ALL or LOAD BIN causes the power supply to generate a
signal to the processor stack that puts the stack
in self-test mode. When stack self-test is completed,
the stack signals
all internal modules on the liD interface to begin their self-tests. The STSC begins
executing
its tests when the module self-tests are completed.
Module Self-Tests
The first level of diagnostics consists of the module self-tests. Self-tests are contained in the replace-
able modules
and are initiated on powerup. (The BASIC language system SCRATCH ALL or
LOAD BIN command causes the execution of all module self tests, except the processor stack tests.
No eqUivalent
HP-UX commands exist.) The user can initiate execution of some self-tests on an
individual basis.
In most cases, LEDs on the modules indicate the results. On some modules, more
information
is available via a self-test status register which is accessible via the operating system.
Module self-tests provide low level diagnostics which can diagnose a problem to the replaceable
module level even
if the CPU or lOP bus has also failed. Each module's self-test is independent of
the functionality of other modules.
Self-Test Supervisory Code
The STSC is resident in the operating system. The device driver calls the STSC for each module,
and the STSC reports the status of the module. The STSC resides in the device driver itself in some
cases, verifying the integrity of the interface
and passing the test results to the operating system.
The
STSC verifies the liD interconnection between the lOP and the internal liD devices, reads the
self-test status registers of those modules, and reports any errors to the user. The code enhances the
module self-tests by further module testing.
Several output devices indicate successful completion of the tests. Thus, the failure of a single
output device can
be distinguished from the failure of another device's self-test.
System Functional Tests
System Functional tests are compiled programs that run on the BASIC 2. a operating system. (The
tests can also run
on a special test operating system that is on the discs with the tests. This is for HP
use only). The programs are capable of testing all internal computer hardware and liD cards to at
least a
95% confidence level. The information returned is detailed enough to enable isolation to a
field-replaceable module. The programs reside
on flexible discs, and the procedures are in the
System Functional Test
User's manual.
09020-90037. rev U~5

HP 9020 Specifications

General

Brand	HP
Model	9020
Category	Desktop
Language	English