Intel SX220 manual 130, Post Codes, Post Diagnostic LED Decoder, Code Description

nibble is represented by a red LED and each bit in the lower nibble is represented by a green LED. If both bits are set in the upper and lower nibble then both red and green LEDs are lit, resulting in an amber colour. Likewise, if both bits are clear then the red and green LEDs are off.

During the POST process, each light sequence represents a specific Port-80 POST code. If a system should hang during POST, the Diagnostic LEDs will present the last test executed before the hang. When reading the lights, the LEDs should be observed from the back of the system. The most significant bit (MSB) is the first LED on the left, and the least significant bit (LSB) is the last LED on the right.

NOTE: When comparing a diagnostic LED colour string from the baseboard to those listed in the diagnostic LED decoder in the following tables, the LEDs on the baseboard should be referenced when viewed by looking into the system from the back. Reading the LEDs from left to right, the Hi bit is located on the left.

Table 41 : POST Codes

Post	Diagnostic LED Decoder
	G=Green, R=Red, A=Amber
Code					Description
	MSB			LSB
07h	Off	G	G	G	Uncompress various BIOS Modules
08h	G	Off	Off	Off	Verify password Checksum
08h	G	Off	Off	Off	Verify CMOS Checksum.
07h	Off	G	G	G	Read Microcode updates from BIOS ROM.
07h	Off	G	G	G	Initialising the processors. Set up processor registers. Select least featured
					processor as the BSP.
0Bh	G	Off	G	G	Hook before the keyboard BAT command is issued.
0Ch	G	G	Off	Off	Keyboard Controller Test: The keyboard controller input buffer is free. Next,
					issuing the BAT command to the keyboard controller
0Eh	G	G	G	Off	Init after Keyboard Test: The keyboard controller BAT command result has
					been verified. Next, performing any necessary initialisation after the
					keyboard controller BAT command test.
0Fh	G	G	G	G	Write Command Byte 8042: The initialisation after the keyboard controller
					BAT command test is done. The keyboard command byte will be written
					next.
10h	Off	Off	Off	R	Keyboard Init: The keyboard controller command byte is written. Next,
					issuing the pin 23 and 24 blocking and unblocking commands
10h	Off	Off	Off	R	Disable and initialise 8259
11h	Off	Off	Off	A	Detect Configuration Mode, such as CMOS clear.
13h	Off	Off	G	A	Chipset Initialisation before CMOS initialisation
					Continued

130 Viglen SX220 User Guide