DC Status 

This green LED is lit to indicate that all DC outputs from the power supply are functional. 

Fault 

This yellow LED is lit to indicate a fault in the power supply. The power supply is non-functional and there is no DC output to the system. The yellow LED on the system front panel also lights if this LED is lit. 

AC-Present 

This green LED is lit to indicate that the primary circuit has power. When this LED is lit, the power supply is providing standby power to the system.