Use this information as an overview of light path diagnostics.
Light path diagnostics is a system of LEDs on the control panel and on various internal components of the blade server or expansion unit. When an error occurs, LEDs can be lit throughout the blade server or expansion unit to help identify the source of the error.
After you remove the blade server or expansion unit, you can press and hold the power button for a maximum of 25 seconds to light the LEDs and locate the failing component.