Dell R 420 Manual

							1.screws (2)
2.power supply cables to the system board (3)
3.power supply cable to the hard-drive 
backplane
4.standoffs (2)
5.power distribution board
6.fan cable connector
Installing The Power Distribution Board
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.Align the power distribution board with the standoffs on the chassis.
2.Install the two screws that secure the power distribution board to the chassis.
3.Connect the power distribution cables to the system board and fan cable connector to the power distribution board.
4.Install the PDB shroud.
5.Close the system.
6.Reconnect the system to its electrical outlet and turn the system on, including any attached peripherals.
System Board
Removing The System Board
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: If you are using the Trusted Program Module (TPM) with an encryption key, you may be prompted to 
create a recovery key during program or System Setup. Be sure to create and safely store this recovery key. If you 
replace this system board, you must supply the recovery key when you restart your system or program before you  can access the encrypted data on your hard drives.
1.Turn off the system, including any attached peripherals, and disconnect the system from the electrical outlet.
2.If installed, remove the front bezel.
3.Open the system.
4.Remove the following:
a)cooling shroud
b)PDB shroud
c)memory modules
d)expansion cards and the expansion-card risers
e)integrated storage controller card
WARNING: The heat sink and processor are hot to the touch for some time after the system has been 
powered down. Allow the heat sink and processor to cool before handling them.
f)heat sink/heat-sink blank and processor/processor blank
g)integrated storage controller card
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							h)internal dual SD module
i)expansion card holder
NOTE: It is recommended that you remove the power distribution board before removing the system board 
from the chassis.
5.Disconnect all other cables from the system board.
CAUTION: Do not lift the system board assembly by grasping a memory module, processor, or other 
components.
6.Remove the nine screws on the system board and slide the system board toward the front of the system.
7.Slide the system board toward the front of the system.
Figure 60. Removing and Installing the System Board
1.screws (9)
2.system board
Installing The System Board
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.Unpack the new system board assembly.
2.Transfer the following components to the new system board:
a)heat sink(s)/heat-sink blank(s) and processors(s)/processor blank(s)
b)memory modules and memory module blanks
CAUTION: Do not lift the system board assembly by grasping a memory module, processor, or other 
components.
CAUTION: Take care not to damage the system identification button while placing the system board into the 
chassis.
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							3.Hold and align the system board by its edges and align it to the back of the chassis.
4.Lower the system board and align the screw holes to the standoffs on the chassis till firmly seated.
5.Tighten the screws of the system board to secure the system board to the chassis.
6.Replace the following:
a)expansion card holder
b)expansion-card risers
c)expansion cards
d)integrated storage controller card
e)memory modules
f)internal dual SD module
g)PDB shroud
h)cooling shroud
7.Reconnect all cables to the system board.
NOTE: Ensure that the cables inside the system are routed secured using the cable securing latches.
8.Close the system.
9.Reconnect the system to its electrical outlet and turn the system on, including any attached peripherals.
10.Import your new or existing iDRAC Enterprise license. For more information, see iDRAC7 User's Guide, under 
Software → Systems Management → Dell Remote Access Controllers, at dell.com/support/manuals.
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							4
Troubleshooting Your System
Safety First—For You And Your System
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.
Troubleshooting System Startup Failure
•If you boot the system to the BIOS boot mode after installing an operating system from the UEFI Boot Manager, the 
system hangs. The reverse is also true. You must boot to the same boot mode in which you installed the operating  system.
•For all other startup issues, note the system messages that appear on the screen.
Troubleshooting External Connections
Ensure that all external cables are securely attached to the external connectors on your system before troubleshooting any external devices.
Troubleshooting The Video Subsystem
1.Check the system and power connections to the monitor.
2.Check the video interface cabling from the system to the monitor.
3.Run the appropriate diagnostic test.
If the tests run successfully, the problem is not related to video hardware.
If the tests fail, see Getting Help.
Troubleshooting A USB Device
Use the following steps to troubleshoot a USB keyboard/mouse. For other USB devices, go to step 7.
1.Disconnect the keyboard and mouse cables from the system briefly and reconnect them.
2.Connect the keyboard/mouse to the USB port(s) on the opposite side of the system.
3.If the problem is resolved, restart the system, enter the System Setup, and check if the non-functioning USB ports 
are enabled.
4.Replace the keyboard/mouse with another working keyboard/mouse.
5.If the problem is resolved, replace the faulty keyboard/mouse.
6.If the problem is not resolved, proceed to the next step to begin troubleshooting the other USB devices attached to  the system.
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							7.Power down all attached USB devices and disconnect them from the system.
8.Restart the system and, if your keyboard is functioning, enter the System Setup. Verify that all USB ports are 
enabled on the 
Integrated Devices screen, in the System Setup options.
If your keyboard is not functioning, you can also use remote access. If the system is not accessible, reset the 
NVRAM_CLR jumper inside your system and restore the BIOS to the default settings.
9.Reconnect and power on each USB device one at a time.
10.If a device causes the same problem, power down the device, replace the USB cable with a known good cable, and  power up the device.
If all troubleshooting fails, see Getting Help.
Troubleshooting A Serial I/O Device
1.Turn off the system and any peripheral devices connected to the serial port.
2.Swap the serial interface cable with a working cable, and turn on the system and the serial device.
If the problem is resolved, replace the interface cable with a known good cable.
3.Turn off the system and the serial device, and swap the device with a comparable device.
4.Turn on the system and the serial device.
If the problem persists, see Getting Help.
Troubleshooting A NIC
1.Run the appropriate diagnostic test.
2.Restart the system and check for any system messages pertaining to the NIC controller.
3.Check the appropriate indicator on the NIC connector:
–If the link indicator does not light, check all cable connections.
–If the activity indicator does not light, the network driver files might be damaged or missing.
Remove and reinstall the drivers if applicable. See the NIC's documentation.
–If applicable, change the autonegotiation setting.
–Use another connector on the switch or hub.
4.Ensure that the appropriate drivers are installed and the protocols are bound. See the NIC's documentation.
5.Enter the System Setup and confirm that the NIC ports are enabled on the Integrated Devices Screen.
6.Ensure that the NICs, hubs, and switches on the network are all set to the same data transmission speed and 
duplex. See the documentation for each network device.
7.Ensure that all network cables are of the proper type and do not exceed the maximum length.
If all troubleshooting fails, see Getting Help.
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							Troubleshooting A Wet System
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 and attached peripherals, and disconnect the system from the electrical outlet.
2.Open the system.
3.Disassemble components from the system:
–Hard drives
–Hard-drive backplane
–USB memory key
–Cooling shroud
–Expansion cards
–Power supply(s)
–Cooling fans
–Processor(s) and heat sink(s)
–Memory modules
4.Let the system dry thoroughly for at least 24 hours.
5.Reinstall the components you removed in step 3.
6.Close the system.
7.Turn on the system and attached peripherals.
If the system does not start properly, see Getting Help.
8.If the system starts properly, shut down the system and reinstall all of the expansion cards that you removed.
9.Run the appropriate diagnostic test.
If the tests fail, see Getting Help.
Troubleshooting A Damaged System
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 and attached peripherals, and disconnect the system from the electrical outlet.
2.Open the system.
3.Ensure that the following components are properly installed:
–Cooling shroud
–Expansion cards
–Power supply(s)
–Cooling fans
–Processor(s) and heat sink(s)
–Memory modules
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							–Hard-drive carriers
–Hard-drive backplane
4.Ensure that all cables are properly connected.
5.Close the system.
6.Run the system board tests in the system diagnostics.
If the tests fail, see Getting Help.
Troubleshooting The System Battery
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: If the system is turned off for long periods of time (for weeks or months), the NVRAM may lose its system 
configuration information. This situation is caused by a defective battery.
1.Re-enter the time and date in the System Setup.
2.Turn off the system and disconnect it from the electrical outlet for at least one hour.
3.Reconnect the system to the electrical outlet and turn on the system.
4.Enter the System Setup.
If the date and time are not correct in the System Setup, check the SEL for system battery messages.
If the problem is not resolved, see Getting Help.
NOTE: Some software may cause the system time to speed up or slow down. If the system seems to operate 
normally except for the time kept in the System Setup, the problem may be caused by software rather than by a 
defective battery.
Troubleshooting Power Supplies
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.Reseat the power supply by removing and reinstalling it.
NOTE: After installing a power supply, allow several seconds for the system to recognize the power supply 
and to determine if it is working properly.
2.If the problem persists, see Getting Help.
Troubleshooting Cooling Problems
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.
Ensure that none of the following conditions exist:
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							•System cover, cooling shroud, EMI filler panel, memory-module blank, or back-filler bracket is removed.
•Ambient temperature is too high.
•External airflow is obstructed.
•A cooling fan is removed or has failed.
•The expansion card installation guidelines have not been followed.
Troubleshooting Cooling Fans
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.Open the system.
2.Reseat the fan or the fan's power cable.
3.If the fan functions properly, close the system.
If the problem persists, see Getting Help.
Troubleshooting System Memory
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 the system is operational, run the appropriate diagnostic test. See Using System Diagnostics for available 
diagnostic tests.
If diagnostics indicates a fault, follow the corrective actions provided by the diagnostic program.
2.If the system is not operational, turn off the system and attached peripherals, and unplug the system from the 
power source. Wait at least 10 seconds and then reconnect the system to power.
3.Turn on the system and attached peripherals and note the messages on the screen.
If an error message is displayed indicating a fault with a specific memory module, go to step 12.
4.Enter the System Setup and check the system memory setting. Make any changes to the memory settings, if 
needed.
If the memory settings match the installed memory but a problem is still indicated, go to step 12.
5.Turn off the system and attached peripherals, and disconnect the system from the electrical outlet.
6.Open the system.
7.Check the memory channels and ensure that they are populated correctly.
8.Reseat the memory modules in their sockets.
9.Close the system.
10.Enter the System Setup and check the system memory setting.
If the problem is not resolved, proceed with the next step.
11.Open the system.
12.If a diagnostic test or error message indicates a specific memory module as faulty, swap or replace the module  with a known good memory module.
13.To troubleshoot an unspecified faulty memory module, replace the memory module in the first DIMM socket with a  module of the same type and capacity.
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							If an error message is displayed on the screen, this may indicate a problem with the installed DIMM type(s), 
incorrect DIMM installation, or defective DIMM(s). Follow the on-screen instructions to resolve the problem. For 
more information, see General Memory Module Installation Guidelines.
14.Close the system.
15.As the system boots, observe any error message that is displayed and the diagnostic indicators on the front of the 
system.
16.If the memory problem is still indicated, repeat step 12 through step 15 for each memory module installed.
If the problem persists after all memory modules have been checked, see Getting Help.
Troubleshooting An Internal USB Key
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.Enter the System Setup and ensure that the USB key portis enabled from the Integrated Devices screen.
2.Turn off the system and attached peripherals, and disconnect the system from the electrical outlet.
3.Open the system.
4.Locate the USB key and reseat it.
5.Close the system.
6.Turn on the system and attached peripherals and check if the USB key is functioning.
7.If the problem is not resolved, repeat step 2 and step 3.
8.Insert a different USB key that you know works properly.
9.Close the system.
If the problem is not resolved, see Getting Help.
Troubleshooting An SD Card
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: Certain SD cards have a physical write-protect switch on the card. If the write-protect switch is turned on 
then the SD card is not writeable.
1.Enter the System Setup and ensure that the Internal SD Card Port is enabled.
2.Turn off the system, including any attached peripherals, and disconnect the system from the electrical outlet.
3.Open the system.
CAUTION: If the Internal SD Card Redundancy option is set to Mirror Mode in the Integrated Devices screen 
of the System Setup, you must follow the instructions in step 4 through step 7 to avoid loss of data.
NOTE: When an SD card failure occurs, the internal dual SD module controller notifies the system. On the next 
reboot, the system displays a message indicating the failure.
4.If the Internal SD Card Redundancy option is set to Disabled, replace the failed SD card with a new SD card.
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