Appendix C: Led Decoder; Figure 147. Diagnostic Led Placement Diagram - Intel S2600CP Service Manual

Appendix C: 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, the
Diagnostic LEDs can be used to identify the last POST process that was executed.
Each POST code is represented by a sequence of 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", and the diagnostic LED #0 is labeled as "LSB".
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Intel Server Board S2600CP Intel
A System Status LED
B System Identification LED
LSB 123456 MSB POST Code Diagnostic LEDs

Figure 147. Diagnostic LED Placement Diagram

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Server System P4000CP Family Service Guide (Preliminary)
Appendix C: LED Decoder
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