Dell PowerEdge 1750 - Manual (Page 8)

Power-Supply Features
Each hot-pluggable power supply has three indicators, visible when the system covers are open, that indicate whether power is present or whether a power
fault has occurred. See Figure 3 -5 and Table 3 -4 for more information about the indicators. See " System Covers " for information about accessing the inside of
the system.
Figure 3-5. Power-Supply Features
Table 3-4. Power-Supply Indicator Patterns
System Messages
System messages alert you to a possible operating system problem or to a conflict between the software and hardware. Table 3 -5 lists the system error
messages that can occur and the probable cause for each message.
Indicator Indicator Code
Line status Green indicates that a valid power source is connected to the system.
Power-supply fault Red indicates a problem with the power supply.
Power-supply status Green indicates that the power supply is operational.
NOTE: If you receive a system message that is not listed in Table 3 -5 , check the documentation for the application that is running when the message
appears or the operating system's documentation for an explanation of the message and recommended action.