Lenovo x3550 M4 Installation And Service Manual page 156

Note: You must turn on the server for the DC LED on the power supply to be lit.
The following illustration shows the locations of the power-supply LEDs on the ac
power supply.
Figure 89. AC power-supply LEDs
The following table describes the problems that are indicated by various
combinations of the power-supply LEDs on an ac power supply and suggested
actions to correct the detected problems.
AC power-supply LEDs
AC DC
On On
Off Off
Off Off
Off On
Off On
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System x3550 M4 Type 7914: Installation and Service Guide
Error (!) Description
Off Normal operation.
Off No ac power to the
server or a problem
with the ac power
source.
On The power supply
has failed.
Off The power supply
has failed.
On The power supply
has failed.
Action
1. Check the ac power to the
server.
2. Make sure that the power
cord is connected to a
functioning power source.
3. Restart the server. If the error
remains, check the
power-supply LEDs.
4. If the problem remains,
replace the power-supply.
Replace the power supply.
Replace the power supply.
Replace the power supply.
Notes
This is a normal
condition when no ac
power is present.