Skip to main content

Power supply LEDs

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

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

  • One processor

  • One DDR5 DRAM memory modules in slot 3 (DIMM3)

  • One power supply unit in PSU bay 1 (PSU1)

  • One M.2 boot drive (if OS is needed for debugging)

  • Five system fans

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

Figure 1. Power supply LEDs
Power supply LEDs
LEDDescription
1 Input status
The input status LED can be in one of the following states:
  • Off: The power supply is disconnected from the AC power source.

  • Green: The power supply is connected to the AC 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 is not working properly. If the server is powered on but the output status LED is off, replace the power supply.

  • Blinking green (about one flash each second): The power supply is in zero-output mode (standby). When the server power load is low, one of the installed power supplies enters into the standby state while the other one delivers entire load. When the power load increases, the standby power supply will switch to active state to provide sufficient power to the server.

    Zero-output mode can be disabled via Lenovo XClarity Controller web interface. 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.

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

3 Fault LED
  • Off: The power supply is working normally

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