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 system supports the Hot Spare feature that significantly reduces the power overhead associated with power 
supply redundancy.
When the Hot Spare feature is enabled, a redundant power supply is switched to a sleep state. The active power supply 
supports 100% of the load, thus operating at higher efficiency. The redundant power supply in the sleep state monitors 
output voltage of the active power supply. If the output voltage of the active power supply drops, the redundant power 
supply in the sleep state returns to an active output state.
The active power supply can also activate a sleeping power supply if having both power supplies active is more efficient 
than having the redundant power supply in a sleep state. The power supply defaults are to wake both power supplies if 
the load on the active power supply is greater than 50% and to sleep the redundant power supply if the load falls below 
20%.
You can configure the Hot Spare feature using the iDRAC settings. For more information on iDRAC settings, see the 
iDRAC7 User's Guide underSoftware → Systems Management → Dell Remote Access Controllers , at dell.com/support/
manuals
.
Removing A Redundant Power Supply
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.
CAUTION: The system requires one power supply for normal operation. On power-redundant systems, remove and 
replace only one power supply at a time in a system that is powered on.
1.Disconnect the power cable from the power source.
2.Disconnect the power cable from the power supply and remove the straps that bundle and secure the system  cables.
NOTE: You may have to unlatch and lift the optional cable management arm if it interferes with power-supply 
removal. For information about the cable management arm, see the system’s rack documentation.
3.Press the release latch and pull the power supply straight out to release it from the power distribution board and 
clear the chassis.
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							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 
place.
NOTE: If you unlatched the cable management arm in step 2 of the previous procedure, relatch it. For 
information about the cable management arm, see the system’s rack documentation.
4.Connect the power cable to the power supply and plug the cable into a power outlet.
CAUTION: When connecting the power cable, secure the cable with the strap.
NOTE: When installing, hot-swapping, or hot-adding a new power supply in a system with two power supplies, 
allow several seconds for the system to recognize the power supply and determine its status. The power-
supply status indicator turns green to signify that the power supply is functioning properly.
Removing A Non-Redundant Power Supply
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.
2.Disconnect the power cable from the power source.
3.Disconnect the power cable from the power supply and remove the straps that bundle and secure the system  cables.
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							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 Supply
1.power supply
2.screw
3.24-pin power cable
4.8-pin power cable
5.standoff
6.SATA power cable
Installing A Non-Redundant Power Supply
NOTE: A hot-swappable non-redundant power supply must be installed in Slot 1 of the power supply bay.
1.Open the system.
2.Align the screw hole on the power supply with the standoff on the chassis.
3.Tighten the screw to secure the power supply to the chassis.
4.Connect all the power cables to the system board, hard drives, and optical drive.
5.Close the system.
6.Connect the power cable to the power supply and plug the cable into a power outlet.
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							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 the power supply blank only in the second power supply bay.
To install the power supply blank, align the blank with the power supply bay and insert it into the chassis until it clicks 
into place.
System Battery
Replacing The System Battery
WARNING: There is a danger of a new battery exploding if it is incorrectly installed. Replace the battery only with 
the same or equivalent type recommended by the manufacturer. See your safety information for additional 
information.
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							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 outlet and 
peripherals.
2.Open the system.
3.Locate the battery socket.
CAUTION: To avoid damage to the battery connector, you must firmly support the connector while installing or 
removing a battery.
4.To remove the battery, support the battery connector by pressing down firmly on the positive side of the connector.
Figure 43. Replacing the System Battery
1.positive side of battery
2.securing tab
5.Lift the battery out of the securing tabs at the negative side of the connector.
6.To install a new system battery, support the battery connector by pressing down firmly on the positive side of the 
connector.
7.Hold the battery with the "+" facing up and slide it under the securing tabs at the positive side of the connector.
8.Press the battery straight down into the connector until it snaps into place.
9.Close the system.
10.Reconnect the system to the electrical outlet and turn the system on, including any attached peripherals
11.Enter the System Setup to confirm that the battery is operating properly.
12.Enter the correct time and date in the System Setup Time and Date fields.
13.Exit the System Setup.
Hard-Drive Backplane
Your system supports:
•Four hard-drive backplane
•Eight hard-drive backplane
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							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, including any attached peripherals, and disconnect the system from the electrical outlet.
3.Open the system.
CAUTION: To prevent damage to the drives and backplane, you must remove the hard drives from the system 
before removing the backplane.
CAUTION: You must note the number of each hard drive and temporarily label them before removal so that 
you can replace them in the same locations.
4.Remove all hard drives.
5.Disconnect the SAS/SATA/SSD data, signal, and power cable(s) from the backplane.
6.Press the release tabs and slide the backplane upward.
Figure 44. Front View of the Four Hard-Drive Backplane
1.hard-drive connectors (4)
2.SAS connector
3.power connector for optical drive
Figure 45. Rear View of the Four Hard-Drive Backplane
1.hard-drive backplane
2.backplane signal connector
3.backplane power connector 
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							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)
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							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)
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							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)
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							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 
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.Use the hooks at the base of the chassis as guides to align the hard-drive backplane.
2.Slide down the hard-drive backplane until the release tabs snap into place.
3.Connect the SAS/SATA/SSD data, signal, and power cable(s) to the backplane.
4.Install the hard drives in their original locations.
5.Close the system.
6.Reconnect the system to its electrical outlet and turn the system on, including any attached peripherals.
7.If applicable, install the front bezel.
Control Panel Assembly
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