Sun Microsystems 5310 NAS manual 7Examples of Post LED Coding

POST LEDs (as viewed from back of server)

= upper nibble bits

= lower nibble bits

RED		GREEN			OFF		AMBER
1	0	0	1	0		0	1	1
high bits							low bits
(on left)							(on right)

POST Code = 95h upper nibble = 1001 = 9h lower nibble = 0101 = 5h

AMBER		RED		GREEN		OFF
1	1	1	0	0	1	0	0
high bits						low bits
(on left)						(on right)

FIGURE 2-7Examples of POST LED Coding

POST Code = CAh upper nibble = 1100 = Ch lower nibble = 1010 = Ah

During the POST process, each light sequence represents a specific Port-80 POST code. If a system should hang during POST, the diagnostic LEDs present the last test executed before the hang. When you read the LEDs, observe them from the back of the system. The most significant bit (MSB) is the leftmost LED, and the least significant bit (LSB) is the rightmost LED.

Note – When comparing a diagnostic LED color sequence from the server Main Board to those listed in the diagnostic LED decoder in the following tables, the LEDs on the Main Board should be referenced when viewed by looking into the system from the back. Reading the LEDs from left to right, the most-significant bit is located on the left.

TABLE 2-15Boot Block POST Progress LED Code Table (Port 80h Codes)

POST	Diagnostic LED Decoder
Code	(G = green, R = red, A = amber)				Description
	MSB			LSB
	MSB			LSB
10h	Off	Off	Off	R	The NMI is disabled. Start power-on delay. Initialization code
					checksum verified.
11h	Off	Off	Off	A	Initialize the DMA controller, perform the keyboard controller BAT
					test, start memory refresh, and enter 4 GB flat mode.

Chapter 2 NAS Head 2-31