Sun Microsystems 60 Post Overview, Pre-POST Preparation, 1Diag-Level Switch Settings

3.1POST 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-levelflag, determine if POST is executed. TABLE 3-1lists the diag-switch?and diag-levelflag settings for disabling POST (off), enabling POST maximum (max), or enabling POST minimum (min).

TABLE 3-1Diag-Level Switch Settings

	POST	Serial Port A	Serial Port A	Diag-Switch?
Diag-Level Setting	Initialization	I/O	Error Output	Setting
Off	No	N/A	N/A	N/A
Max	Yes (power-on)	Enabled	Enabled	True
Min	Yes (power-on)	Disabled	Enabled	True

3.2Pre-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

3-2Sun Ultra 60 Service Manual • August 2001