Sun Microsystems 60 Computer Hardware User Manual


 
3-2 Sun Ultra 60 Service Manual August 2001
3.1 POST Overview
POST is useful in determining if a portion of the system unit has failed and should
be replaced. POST detects approximately 95 percent of system unit faults and is
located in the system board OpenBoot
PROM (OBP). The setting of two NVRAM
variables, the diag-switch? and the diag-level flag, determine if POST is
executed.
TABLE 3-1 lists the diag-switch? and diag-level flag settings for
disabling POST (off), enabling POST maximum (max), or enabling POST minimum
(min).
3.2 Pre-POST Preparation
Pre-POST preparation includes:
Setting up a tip connection to another workstation or terminal to view POST
progress and error messages. See Section 3.2.1, “Setting Up a Tip Connection” on
page 3-3.
Verifying baud rates between a workstation and a monitor or a workstation and a
terminal. See Section 3.2.2, “Verifying the Baud Rate” on page 3-4.
If a terminal or a monitor is not connected to serial port A (default port) of a
workstation or server to be tested, the keyboard LEDs are used to determine error
conditions. See Section 3.7, “System and Keyboard LEDs” on page 3-22
TABLE 3-1 Diag-Level Switch Settings
Diag-Level Setting
POST
Initialization
Serial Port A
I/O
Serial Port A
Error Output
Diag-Switch?
Setting
Off No N/A N/A N/A
Max Yes (power-on) Enabled Enabled True
Min Yes (power-on) Disabled Enabled True