Precautions When Using Post And Obp - Sun Microsystems SPARCcenter 2000 Service Manual

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2.4 Precautions when Using POST and OBP

2.4.1 System Boards with PROM Revision 2.13 (or Higher)
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A system may appear to be hung or not communicating if the terminal is not
connected to the system master board.
PROM revision 2.13 uses auto-master scheme instead of master-nvram scheme
to select the system master board, and then nvram information is automatically
propagated to all boards.
If there is no system hardware error, OBP will select the POST master board (or
the lowest board that has a functional CPU) as the system master board.
The auto-master scheme ignores the status of nvram master or slave.
If any system hardware error occurs after power on, then OBP will use the
master-nvram scheme to select a system master.
To identify the system master while the system is booting, look for the one
board back panel with flashing diagnostic LEDs. Figure 2-1 shows these LEDs
and the CPU LEDs. Diagnostic LEDs on all other system boards will be OFF.
After boot completes, the LED displays change:
•
all system boards with modules display the same cycling LED pattern
•
LEDs on system boards without SPARC modules are ON in a solid pattern
SPARCcenter 2000/2000E Service Manual—June 1996