AT&T 3B2 Off-Line Diagnostic Manual page 20

Procedure$ for Using Diagnostics
The following procedures explain what you need to know to be able to run diagnostics on the 3B2
computer. The procedures are given in sequential order from power up to power down.
Diagnostics Run During Powerup
When the 3B2 computer is powered up, the Power and Diagnostic indicators on the front of the
unit come on simultaneously. After a few seconds, the message SELF-CHECK is displayed on the
system console. This message indicates that the basic system sanity tests have started.
If a basic sanity test fails the Diagnostic indicator will begin flashing in a pattern. The flashes on
the Diagnostic indicator are the only way for you to know that a sanity test failed. The number of
flashes on the Diagnostic indicator represent the following failures:
• 1 flash-The system completed the basic sanity tests and is ready for the firmware password, but
no system console device is connected. Check the console and/or cable connection to the
system.
• 2 flashes-The processor is not working correctly.
• 3 flashes-There are problems in Programmable Read Only Memory (PROM).
• 4 flashes-The Random Access Memory (RAM) (first 16 kilobytes) failed pattern tests.
• 5 flashes-The Dual Universal Asynchronous Receiver/Transmitter (DUART) failed transmission
tests.
For these problems, call your AT&T Service Representative or authorized dealer. By knowing the
number of flashes on the Diagnostic indicator, your AT&T Service Representative or authorized dealer
will have a better idea of the equipment to bring.
If the basic sanity tests pass, the message DIAGNOSTICS is displayed on the system console. The
system then runs all normal diagnostic phases on itself. Demand and interactive diagnostic phases are
not run during powerup.
It
takes approximately 2 minutes for the system to run all of the normal
diagnostics. The exact amount of time required to run diagnostics depends on the system's hardware
configura tion.
The Diagnostic indicator stays on until all of the diagnostics complete successfully or one of the
diagnostics tests fail. If all of the diagnostics pass, the message PASSED is displayed on the system
console after the DIAGNOSTICS message, and the Diagnostic indicator goes off. If a diagnostic test
failed, the message FAILED is displayed after the DIAGNOSTICS message. A SYSTEM FAILURE
message is also displayed when a diagnostic test fails. The Diagnostic indicator remains on after a
diagnostic failure. The system can be placed in the firmware mode by entering the firmware password
(see the procedure "How to Enter Interactive Firmware Mode"). By putting the system into the
firmware mode, you can rerun the diagnostics to determine which diagnostic test failed.
2-2 OFF-LINE DIAGNOSTIC MANUAL