1. Installing Internal Optional DevicesExpress5800/R120d-2M User’s Guide82Chapter 2 Preparations1.16.2 Replacement / RemovalTo remove additional/redundant fan unit, reverse the installation procedure.When replacing the fan unit, fan units are hot-swappable even while the system is powered-on and running.You can identify the failing fan by using the management tool such as EXPRESSSCOPE Engine 3.While the system is powered-on or running, the LED of failed fan unit is lit.CAUTIONBe sure to observe the following precautions to use the server safely. Failure toobserve the precautions may cause burns, injury, and property damage. Fordetails, refer to Safety precautions in Precautions for Use.• Pay attention to electric hazard.