Dell R 420 Manual

Figure 12. Inside the System—With Redundant Power Supplies
1.power distribution board shroud
2.cooling shroud
3.power supply units (2)
4.storage controller card
5.expansion-card riser 2
6.expansion card
7.expansion-card riser 1
8.heat sink for processor 2
9.DIMMs (12)
10.cooling fans (5)
11.optical drive
12.hard drives (4)
13.control panel
14.hard-drive backplane
15.cable routing latch
16.power distribution board
41 

Cooling Shroud
Removing The Cooling Shroud
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: Never operate your system with the cooling shroud...

Installing The Cooling Shroud
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.
NOTE: For proper seating of the cooling shroud in the chassis, ensure that...

NOTE: DIMMs in sockets A1 to A6 are assigned to processor 1 and DIMMs in sockets B1 to B6 are assigned to 
processor 2.
Figure 14. Memory Socket Locations
Memory channels are organized as follows:
Processor 1channel 1: memory sockets A1 and A4
channel 2: memory sockets A2 and A5
channel 3: memory sockets A3 and A6
Processor 2channel 1: memory sockets B1 and B4
channel 2: memory sockets B2 and B5
channel 3: memory sockets B3 and B6
44 

General Memory Module Installation Guidelines
This system supports Flexible Memory Configuration, enabling the system to be configured and run in any valid chipset 
architectural configuration. The following are the recommended guidelines for best performance:
•UDIMMs and RDIMMs must not be mixed.
•x4 and x8 DRAM based DIMMs can be mixed. For more information, see Mode-Specific Guidelines.
•A maximum of two UDIMMs can be populated in a channel.
•A maximum of two quad-rank RDIMMs can be populated in a...

Memory Optimized (Independent Channel) Mode
This mode supports SDDC only for memory modules that use x4 device width and does not impose any specific slot population requirements.
Memory Sparing
NOTE: To use memory sparing, this feature must be enabled in the System Setup.
In this mode, one rank per channel is reserved as a spare. If persistent correctable errors are detected on a rank, the 
data from this rank is copied to the spare rank and the failed rank is disabled.
With memory sparing enabled, the...

System Capacity 
(in GB)DIMM Size (in 
GB)Number of 
DIMMsOrganization and 
SpeedDIMM Slot Population1R x8, 1600 MT/s20451R x8, 1333 MT/s
1R x8, 1600 MT/s
A1, A2, A3, A4, A524832R x4, 1333 MT/s
2R x4, 1600 MT/s
A1, A2, A332842R x4, 1333 MT/s
2R x4, 1600 MT/s
A1, A2, A3, A4481632R x4, 1333 MT/s
2R x4, 1600 MT/s
A1, A2, A3961662R x4, 1333 MT/s
2R x4, 1600 MT/s
A1, A2, A3, A4, A5, A61283244R x4, 1066 MT/sA1, A2, A3, A41923264R x4, 1066 MT/sA1, A2, A3, A4, A5, A6Table 2. Memory Configurations — Two...

Removing Memory Modules
WARNING: The memory modules are hot to the touch for some time after the system has been powered down. 
Allow time for the memory modules to cool before handling them. Handle the memory modules by the card edges 
and avoid touching the components or metallic contacts on the memory module.
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...

Figure 16. Removing The Memory Module
1.memory module/memory-module blank
7.Install the cooling shroud.
8.Close the system.
9.Reconnect the system to its electrical outlet and turn the system on, including any attached peripherals.
Installing Memory Modules
WARNING: The memory modules are hot to the touch for some time after the system has been powered down. 
Allow time for the memory modules to cool before handling them. Handle the memory modules by the card edges 
and avoid touching the components or...

CAUTION: To prevent damage to the memory-module socket during installation, apply pressure at both ends 
of the memory module evenly. Do not apply pressure to the center of the memory module.
7.Press down on the memory module with your thumbs until the memory module snaps into place.
Figure 17. Installing The Memory Module
1.memory module
2.memory-module ejectors
3.memory-module socket alignment key
4.memory-module alignment key
NOTE: When the memory module is properly seated in the socket, the levers on...