Intel SR1695GPRX1AC ユーザーズマニュアル

ページ / 83
Intel® Server System SR1695GPRX TPS  
Appendix B: POST Code LED Decoder 
Revision 1.5 
 
61 
Intel order number: G11332-006 
Appendix B: POST Code LED Decoder 
During the system boot process, the BIOS executes a number of platform configuration 
processes, each of which is assigned a specific hex POST code number. As each configuration 
routine is started, the BIOS displays the POST code to the POST Code Diagnostic LEDs on the 
back edge of the server board. To assist in troubleshooting a system hang during the POST 
process, you can use the diagnostic LEDs to identify the last POST process executed. 
 
Figure 30. Diagnostic LED location 
Table 61. POST Code Diagnostic LED Location 
ID LED  
Status LED 
Diagnostic LED #7 MSB 
Diagnostic LED #3  
Diagnostic LED #6  
Diagnostic LED #2  
Diagnostic LED #5  
Diagnostic LED #1  
Diagnostic LED #4  
Diagnostic LED #0 LSB  
Each POST code is represented by the eight amber diagnostic LEDs. The POST codes are 
divided into two nibbles, an upper nibble and a lower nibble. The upper nibble bits are 
represented by diagnostic LEDs #4, #5, #6, and #7. The lower nibble bits are represented by 
diagnostics LEDs #0, #1, #2, and #3. If the bit is set in the upper and lower nibbles, then the 
corresponding LED is lit. If the bit is clear, then the corresponding LED is off. 
The diagnostic LED #7 is labeled as “MSB” (Most Significant Bit), and the diagnostic LED #0 is 
labeled as “LSB” (Least Significant Bit). 
In the following example, the BIOS sends a value of ACh to the diagnostic LED decoder. The 
LEDs are decoded as follows: