IBM 86655RY Hardware Maintenance Manual - Page 39

SMI NMI SP PCIA PCIB PCIC DASD1 MEM CPU VRM FAN TEMP NON OVER PS1 PS2 PS3 PS4 RED SPEC Light path diagnostics You can use the light path diagnostics built into the server to quickly identify the type of system error that occurred. Your server is designed so that LEDs remain illuminated when the server shuts down, as long as the power supplies are operating properly. This feature helps you to isolate the problem if an error causes the server to shut down. If the system error LED (on the information LED panel) is not lit and no diagnostics panel LEDs are lit, it means that the light path diagnostics have not detected a system error. If the system error LED (on the information LED panel) is lit, it means that a system error was detected. Check to see which of the LEDs on the diagnostics panel inside the server are lit and refer to the following table: Diagnostics 29