DEC Personal DECstation 5000, Руководство пользователя

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Troubleshooting
13.2 Invoking the Powerup Self-Test
13.2 Invoking the Powerup Self-Test
The most straightforward way to invoke the power-up self-test diagnostics is to
power-cycle the system. This is done by simply turning the power off and then
turning it back on.
Note
Power-cycling the machine will result in the erasure of the contents of
memory.
You can also type the commands pst-q or pst-t at the console prompt. pst-t
will run a thorough test. pst-q will run a reduced version of the power-up
self-test. This version tests all major sub-systems, but has been optimized to
execute quickly.
When running the power-up self-test, it is important to either have a device
connected to the Ethernet and SCSI ports, or to install the Ethernet loopback
connector (Part #12-22196-02) and the SCSI terminator (Part #12-29635-01). If
nothing is connected to these ports, the system may report false errors.
The Ethernet diagnostics used by
pst-t
actually send data out onto the network
and then listen for a response. If none is received, an error is reported. The
loopback connector routes this transmitted message back to the system,
thereby enabling the Ethernet diagnostic to test the complete circuit path.
The basic design and architecture of the SCSI bus requires that a terminator
be placed on the connector at the end of the bus. The SCSI I/O bus allows you
to daisy chain up to seven devices together. These devices are most often disk
drives that use the SCSI bus as a party line to communicate with the system.
Note
This chapter focuses on how to use the power-up self-test diagnostics to
isolate problem modules. There are additional diagnostics available to
you. Their use is described in Appendix G.
Troubleshooting 13–3