3. Disconnect all the cables connected to the back of the NAS appliance.4. Remove the controllers from the NAS appliance.5. Remove the NAS appliance from the rack.6. Open the NAS appliance.7. Remove the following:– power supply units– cooling fans– power transmission board assemblies8. Disconnect the front LED status module cable from the midplane board.9. Using a Torx 15 screwdriver, remove the 11 screws securing the midplane board to the NAS appliance chassis.10. Hold the midplane board by its edges and lift it out of the chassis.Figure 18. Removing and Installing the midplane Board1. midplane board2. screws (11)Installing The Midplane BoardCAUTION: Many repairs may only be done by a certified service technician. You should only performtroubleshooting and simple repairs as authorized in your product documentation, or as directed by the online ortelephone service and support team. Damage due to servicing that is not authorized by Dell is not covered by yourwarranty. Read and follow the safety instructions that came with the product.WARNING: Whenever you need to lift the NAS appliance, get others to assist you. To avoid injury, do not attempt tolift the system by yourself.NOTE: This is a service only procedure.1. Unpack the new midplane board.2. Hold the midplane board by its edges and lower it into the NAS appliance chassis.3. Align the screw holes on the midplane board with the standoffs on the chassis.30