Dell R 420 Manual

When two identical power supplies are installed, the power supply configuration is redundant (1 + 1). In redundant mode, power is supplied to the system equally from both power supplies to maximize efficiency.
When only one power supply is installed, the power supply configuration is non-redundant (1 + 0). Power is supplied to 
the system only by the single power supply.
NOTE: If two power supplies are used, they must be of the same type and have the same maximum output power.
Hot Spare Feature
Your...

Figure 40. Removing and Installing a Redundant Power Supply
1.redundant power supply unit
2.release latch
3.power supply handle
Installing A Redundant Power Supply
1.Verify that both power supplies are the same type and have the same maximum output power.
NOTE: The maximum output power (shown in Watts) is listed on the power supply label.
2.If applicable, remove the power supply blank.
3.Slide the new power supply into the chassis until the power supply is fully seated and the release latch snaps into...

NOTE: You may have to unlatch and lift the optional cable management arm if it interferes with the power-
supply removal. For information about the cable management arm, see the system’s rack documentation.
4.Open the system.
5.Disconnect all the power cables from the power supply to the system board, hard drives, and optical drive.
6.Remove the screw securing the power supply to the chassis, slide and lift the power supply out of the chassis.
Figure 41. Removing and Installing a Non-Redundant Power...

Removing The Power Supply Blank
CAUTION: To ensure proper system cooling, the power supply blank must be installed in the second power supply 
bay in a non-redundant configuration. Remove the power supply blank only if you are installing a second power 
supply.
If you are installing a second power supply, remove the power supply blank in the bay by pulling outward on the  blank.
Figure 42. Removing and Installing the Power Supply Blank
1.power supply blank
Installing The Power Supply Blank
NOTE: Install...

CAUTION: Many repairs may only be done by a certified service technician. You should only perform 
troubleshooting and simple repairs as authorized in your product documentation, or as directed by the online or 
telephone service and support team. Damage due to servicing that is not authorized by Dell is not covered by your 
warranty. Read and follow the safety instructions that came with the product.
1.Turn off the system, including any attached peripherals, and disconnect the system from the electrical...

Removing The Hard-Drive Backplane
CAUTION: Many repairs may only be done by a certified service technician. You should only perform 
troubleshooting and simple repairs as authorized in your product documentation, or as directed by the online or 
telephone service and support team. Damage due to servicing that is not authorized by Dell is not covered by your 
warranty. Read and follow the safety instructions that came with the product.
1.If installed, remove the front bezel
2.Turn off the system,...

Figure 46. Removing and Installing the Four Hard-Drive Backplane
1.release tabs (2)
2.hard-drive backplane
3.guide pins (2)
4.chassis hooks (4)
87 

Figure 47. Cabling Diagram—Four Hard-Drive Backplane
1.system board
2.hard-drive backplane
3.SAS cable connector
4.cable routing guide
5.signal cable connector
6.power cable connector
7.cable routing latch
8.power distribution board
9.cable retention latch
Figure 48. Front View of the Eight Hard-Drive Backplane
1.hard-drive connectors (8)
88 

Figure 49. Rear View of the Eight Hard-Drive Backplane
1.SAS B connector
2.SAS A connector
3.backplane power connector
4.backplane signal connector
Figure 50. Removing and Installing the Eight Hard-Drive Backplane
1.hard-drive backplane
2.release tabs (2)
3.chassis hooks (4)
89 

Figure 51. Cabling Diagram—Eight Hard-Drive Backplane
1.system board
2.hard-drive backplane
3.SAS B cable connector
4.SAS A cable connector
5.power cable connector
6.signal cable connector
7.cable routing latch
8.power distribution board
9.cable retention latch
Installing The Hard-Drive Backplane
CAUTION: Many repairs may only be done by a certified service technician. You should only perform 
troubleshooting and simple repairs as authorized in your product documentation, or as directed by the online or...