Post Progress And Error Reporting; Additional Keyboard Control Commands - Sun Microsystems Ultra 1 Series Service Manual

POST Progress and Error Reporting

While POST is running, observe the Caps Lock key on the system keyboard. It
should flash on and off to indicate that tests are running. Additional POST progress
indication is visible when a terminal or tip line is connected to serial port A.
If an error occurs during POST, the Caps Lock key will stop flashing and an error
code will be displayed using the lights on the keyboard"s Caps Lock, Compose,
Scroll Lock, and Num Lock keys.
Note -
The error code may only be visible for a few seconds, so it is important to
observe the keyboard lights closely while POST is running.
If an error code is present on the keyboard, compare the pattern to Table 3–1 for the
meaning of the failure. The failure code will indicate a part of the system hardware
that was tested by POST to be defective or missing.
In most cases, POST will also attempt to send a failure message to the system
monitor. In this case, a message such as this will be displayed:
Power On Self Test Failed. Cause: SIMM U0701 or System Board
ok
The system will not automatically boot if a POST error occurs. It will halt at the ok
prompt to alert the user of the failure.
Additional Keyboard Control
Commands
4 Stop Key
If the diag-switch? variable is set to true but you want to bypass POST when the
system is powered on, press and hold the Stop key on the keyboard and turn on the
system power. This causes POST to be bypassed.
4 Stop and N Keys
If you want to return the system"s NVRAM parameters to their original default
settings, press and hold the Stop and N keys before powering on the system.
Continue to hold the Stop and N keys until the system banner appears on the
monitor.
9
Power-On Self-Test (POST)