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LEDs on the power supply unit

This topic provides information about various power supply unit LED status and corresponding action suggestions.

The following minimal configuration is required for the server to start:

  • One processor in processor socket 1

  • One memory module in slot 7

  • One power supply unit

  • One HDD/SSD drive, one M.2 drive, or one 7mm drive (if OS is needed for debugging)

  • Six system fans (with one processor)

The following table describes the problems that are indicated by various combinations of the power-supply unit LEDs and the power-on LED and suggested actions to correct the detected problems.

Figure 1. LEDs on the power supply unit
Power supply LEDs

LEDDescription
1 Input status
The input status LED can be in one of the following states:

  • Off: The power supply unit is disconnected from the input power source.

  • Green: The power supply unit is connected to the input power source.

2 Output status
The output status LED can be in one of the following states:

  • Off: The server is powered off, or the power supply unit is not working properly. If the server is powered on but the output status LED is off, replace the power supply unit.

  • Slow blinking green (about one flash every two seconds): The power supply unit is in cold redundancy active mode.

  • Fast blinking green (about 2 flashes each second): The power supply unit is in cold redundancy sleep mode.

  • Green: The server is on and the power supply unit is working normally.

Zero-output mode can be disabled via Setup utility or Lenovo XClarity Controller web interface. If you disable zero-output mode, both power supplies will be in the active state.

  • Start the Setup utility, go to System Settings > Power > Zero Output and select Disable. If you disable zero-output mode, both power supplies will be in the active state.

  • Log in to the Lenovo XClarity Controller web interface, choose Server Configuration > Power Policy, disable Zero Output Mode, and then click Apply.

3 Fault LED

  • Off: The power supply unit is working normally.

  • Yellow: The power supply unit may have failed. Dump the FFDC log from the system and contact Lenovo back end support team for PSU data log reviewing.