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Before You Begin: Dell Dimension E520 Service Manual
Back to Contents Page
Before You Begin
Dell™ Dimension™ E520 Service Manual
Getting StartedRecommended ToolsTurning Off Your ComputerBefore Working Inside Your Computer
Getting Started
This manual provides procedures for removing and replacing the components in your computer. Unless otherwise noted, each
procedure assumes that the following conditions exist:
You have performed the steps in Turning Off Your Computer and Before Working Inside Your Computer.
You have read the safety information in your Dell™ Product Information Guide.
A component can be replaced by performing the removal procedure in reverse order.
Recommended Tools
The procedures in this document may require the following tools:
Small flat-blade screwdriver
Phillips screwdriver
Flash BIOS update program (download)
Turning Off Your Computer
NOTICE: To avoid losing data, save and close any open files and exit any open programs before you turn off your
computer.
1. Shut down the operating system:
a. Save and close any open files, exit any open programs, click the Start button, and then click Shutdown.
b. In the Shut Down Windows window, select Shut down.
The computer turns off after the operating system shutdown process finishes.
2. Ensure that the computer and any attached devices are turned off. If your computer and attached devices did not
automatically turn off when you shut down your operating system, press and hold the power button for 4 seconds.
Before You Begin: Dell Dimension E520 Service Manual
Use the following safety guidelines to help protect your computer from potential damage and to help ensure your own
personal safety.
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the
Product Information Guide.
CAUTION: Handle components and cards with care. Do not touch the components or contacts on a card.
Hold a card by its edges or by its metal mounting bracket. Hold a component such as a processor by its
edges, not by its pins.
NOTICE: Only a certified service technician should perform repairs on your computer. Damage due to servicing that is
not authorized by Dell is not covered by your warranty.
NOTICE: When you disconnect a cable, pull on its connector or on its strain-relief loop, not on the cable itself. Some
cables have a connector with locking tabs; if you are disconnecting this type of cable, press in on the locking tabs
before you disconnect the cable. As you pull connectors apart, keep them evenly aligned to avoid bending any
connector pins. Also, before you connect a cable, ensure that both connectors are correctly oriented and aligned.
NOTICE: To avoid damaging the computer, perform the following steps before you begin working inside the computer.
1. Turn off your computer. See Turning Off Your Computer
NOTICE: To disconnect a network cable, first unplug the cable from your computer, and then unplug it from the
network port or device.
2. Disconnect any telephone or telecommunication lines from the computer.
3. Disconnect your computer and all attached devices from their electrical outlets, and then press the power button to
ground the system board.
.
NOTICE: Before touching anything inside your computer, ground yourself by touching an unpainted metal surface,
such as the metal at the back of the computer. While you work, periodically touch an unpainted metal surface to
dissipate any static electricity that could harm internal components.
Use the Service Tag to identify your computer when you access the Dell
Support website or contact support.
Use this latch to remove the cover.
The CD or DVD drive light is on when the computer reads data from, or writes
data to the CD or DVD drive.
Press the CD or DVD eject button to eject a disc from the CD or DVD drive.
About Your Computer: Dell Dimension E520 Service Manual
drive
6ventsFor adequate cooling, do not block any of the vents.
NOTICE: Ensure that there is a minimum of two inches of space between all
vents and any objects near the vents.
NOTICE: Keep the vent area clean and dust-free to ensure that the system is
adequately ventilated. Use only a dry cloth to clean the vent area to avoid
water damage to the system.
7USB 2.0
connectors
(2)
8power
button
9hard drive
activity
light
10 diagnostic
lights (4)
11 headphone
connector
12 microphone
connector
Use the front USB connectors for devices that you connect occasionally, such
as flash memory keys, cameras, or bootable USB devices. For more
information on booting to a USB device see System Setup Options
NOTE: It is recommended that you use the back USB connectors for devices
that typically remain connected, such as printers and keyboards.
Press the power button to turn on the computer.
NOTICE: To avoid losing data, do not use the power button to turn off the
computer. Instead, perform an operating system shutdown.
The hard drive light is on when the computer reads data from or writes data
to the hard drive. The light may also be on when a device such as a CD player
is operating.
Use the sequence of the diagnostic lights to help you troubleshoot a problem
with your computer (see Diagnostic Lights
Use the headphone connector to attach headphones and most kinds of
speakers.
Use the microphone connector to attach a personal computer microphone for
voice or musical input into a sound or telephony program.
About Your Computer: Dell Dimension E520 Service Manual
1 power
connector
2 back I/O
connectors
3 card slots (4) Access connectors for installed PCI or PCI Express cards.
Insert the power cable.
Plug USB, network, VGA monitor, and audio devices into the appropriate
connectors (see Back Panel Connectors
).
Back Panel Connectors
1link integrity
light
Green — A good connection exists between a 10-Mbps network
and the computer.
Orange — A good connection exists between a 100-Mbps network
and the computer.
Yellow — A good connection exists between a 1000-Mbps (1Gbps) network and the computer.
Off — The computer is not detecting a physical connection to the
network.
NOTICE: Do not plug a telephone cable into the network connector.
About Your Computer: Dell Dimension E520 Service Manual
Use the network adapter connector to attach your computer to a
network or broadband device. Connect one end of a network cable to
either a network jack or your network or broadband device, and then
connect the other end of the network cable to the network adapter
connector on your computer. A click indicates that the network cable
has been securely attached.
On computers with an additional network card, use the connectors on
the card and on the back of the computer when setting up multiple
network connections (such as a separate intra- and extranet).
NOTE: It is recommended that you use Category 5 wiring and
connectors for your network. If you must use Category 3 wiring, force
the network speed to 10 Mbps to ensure reliable operation.
3network activity
light
4USB 2.0
connectors (2)
(rear dual)
5USB 2.0
connectors (4)
(rear quad)
6surround sound
connector
7line-in connectorUse the (blue) line-in connector to attach a record/playback device such
Flashes a yellow light when the computer is transmitting or receiving
network data. A high volume of network traffic may make this light
appear to be in a steady "on" state.
Use the back, rear-dual USB connectors for devices that typically remain
connected, such as printers and keyboards.
NOTE: It is recommended that you use the front USB connectors for
devices that you connect occasionally, such as joysticks, cameras, or
bootable USB devices.
Use the back, rear-quad USB connectors for devices that typically
remain connected, such as printers and keyboards.
NOTE: It is recommended that you use the front USB connectors for
devices that you connect occasionally, such as joysticks, cameras, or
bootable USB devices.
Use the (black) surround sound connector to attach multichannelcapable speakers.
On computers with a sound card, use the connector on the card.
as a cassette player, CD player, or VCR.
On computers with a sound card, use the connector on the card.
8line-
out/headphone
connector
9microphone
connector
10 side surround
sound connector
11 center/subwoofer
LFE connector
Use the (green) line-out connector to attach headphones and most
speakers with integrated amplifiers.
On computers with a sound card, use the connector on the card.
Use the (pink) microphone connector to attach a personal computer
microphone for voice or musical input into a sound or telephony
program.
On computers with a sound card, use the connector on the card.
Use the (gray) side surround sound connector to attach multichannel-
capable speakers. The side-surround output provides enhanced
surround audio for computers with 7.1 speakers.
On computers with a sound card, use the connector on the card.
Use the (orange) center/subwoofer connector to attach a center speaker
or a single subwoofer.
On computers with a sound card, use the connector on the card.
NOTE: The LFE (Low Frequency Effects) Audio channel, found in digital
surround sound audio schemes, carries only low frequency information
of 80 Hz and below. The LFE channel drives a subwoofer to provide
extremely low bass extension. Systems not using subwoofers can shunt
the LFE information to the main speakers in the surround sound setup.
Advanced Troubleshooting: Dell Dimension E520 Service Manual
Back to Contents Page
Advanced Troubleshooting
Dell™ Dimension™ E520 Service Manual
Power LightsDiagnostic LightsBeep CodesSystem MessagesDell DiagnosticsDriversResolving Software and Hardware Incompatibilities
Power Lights
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the
Product Information Guide.
The power button light located on the front of the computer illuminates and blinks or remains solid to indicate different states:
If the power light is green and the computer is not responding:
Ensure the display is connected and powered on.
If the display is connected and powered on see Diagnostic Lights.
If the power light is blinking green, the computer is in standby mode. Press a key on the keyboard, move the mouse,
or press the power button to resume normal operation.
If the power light is off, the computer is either turned off or is not receiving power.
Reseat the power cable in the power connector on the back of the computer and the electrical outlet.
If the computer is plugged into a power strip, ensure that the power strip is plugged into an electrical outlet and
that the power strip is turned on. Also, bypass power protection devices, power strips, and power extension
cables to verify that the computer turns on properly.
Ensure that the electrical outlet is working by testing it with another device, such as a lamp.
Ensure that the main power cable and front panel cable are securely connected to the system board (see System
Board Components).
If the power light is blinking amber, the computer is receiving electrical power, but an internal power problem might
exist.
Ensure that the voltage selection switch is set to match the AC power at your location (if applicable).
If the power light is steady amber, a device might be malfunctioning or incorrectly installed.
Remove and then reinstall the memory modules (see Memory).
Remove and then reinstall any cards (see Cards).
Remove and then reinstall the graphics card, if applicable (see Cards).
Ensure that all power cables are securely connected to the system board (see System Board Components).
Advanced Troubleshooting: Dell Dimension E520 Service Manual
Diagnostic Lights
CAUTION: Before you perform any of the procedures in this section, follow the safety instructions in the
Product Information Guide.
To help you troubleshoot a problem, your computer has four lights labeled 1, 2, 3, and 4 on the front panel (see Front View of
the Computer). When the computer starts normally, the lights flash before turning off. If the computer malfunctions, the
sequence of the lights helps to identify the problem.
.
Light Pattern Problem DescriptionSuggested Resolution
The computer is in a
normal "off" condition or
a possible pre-BIOS
failure has occurred.
All four diagnostic lights
display solid green and
then turn off after the
system successfully boots
to the operating system.
A possible processor
failure has occurred.
Memory modules are
detected, but a memory
failure has occurred.
Plug the computer into a working electrical outlet (see Power Lights).
If the problem persists, contact Dell (see "Contacting Dell" in your
Owner's Manual).
Reseat the processor (see Processor).
If the problem persists, contact Dell (see "Contacting Dell" in your
Owner's Manual).
If two or more memory modules are installed, remove the modules
(see Removing Memory
Memory) and restart the computer. If the computer starts normally,
continue to install additional memory modules (one at a time) until you
have identified a faulty module or reinstalled all modules without
error.
If available, install properly working memory of the same type into
your computer (see Installing Memory
If the problem persists, contact Dell (see "Contacting Dell" in your
Owner's Manual).
), then reinstall one module (see Installing
).
A possible graphics card
failure has occurred.
A possible floppy drive or
hard drive failure has
occurred.
A possible USB failure
has occurred.
No memory modules are
detected.
Memory modules are
detected, but a memory
configuration or
Reseat any installed graphics cards (see Cards).
If available, install a working graphics card into your computer.
If the problem persists, contact Dell (see "Contacting Dell" in your
Owner's Manual).
Reseat all power and data cables.
Reinstall all USB devices and check all cable connections.
If two or more memory modules are installed, remove the modules
(see Removing Memory
Memory) and restart the computer. If the computer starts normally,
continue to install additional memory modules (one at a time) until you
have identified a faulty module or reinstalled all modules without
error.
If available, install properly working memory of the same type into
your computer (see Installing Memory
If the problem persists, contact Dell (see "Contacting Dell" in your
Owner's Manual).
Ensure that no special requirements for memory module/connector
placement exist (see Memory
Ensure that the memory you are using is supported by your computer
Advanced Troubleshooting: Dell Dimension E520 Service Manual
compatibility error has
(see Memory).
occurred.
A possible expansion card
failure has occurred.
The system is operating
in quick resume mode.
Another failure has
occurred.
If the problem persists, contact Dell (see "Contacting Dell" in your
Owner's Manual).
1. Determine if a conflict exists by removing an expansion card (not a
graphics card) and restarting the computer (see Cards
2. If the problem persists, reinstall the card you removed, then remove a
different card and restart the computer.
3. Repeat this process for each card installed. If the computer starts
normally, troubleshoot the last card removed from the computer for
resource conflicts (see Resolving Software and Hardware
Incompatibilities).
4. If the problem persists, contact Dell (see "Contacting Dell" in your
Owner's Manual).
Press the power button
Move the mouse
Press any key on the keyboard
Press any key on the optional MCE remote control
Ensure that all hard drive and CD/DVD drive cables are properly
connected to the system board (see Drives
If there is an error message on your screen identifying a problem with
a device (such as the floppy drive or hard drive), check the device to
make sure it is functioning properly.
If the operating system is attempting to boot from a device (such as
the floppy drive or hard drive), check system setup (see System
Setup) to make sure the boot sequence is correct for the devices
installed on your computer.
If the problem persists, contact Dell (see "Contacting Dell" in your
Owner's Manual).
).
).
Beep Codes
Your computer might emit a series of beeps during start-up if the monitor cannot display errors or problems. This series of
beeps, called a beep code, identifies a problem. For example, beep code 1-3-1 (one possible beep code) consists of one beep,
a burst of three beeps, and then one beep. This beep code tells you that the computer encountered a memory problem.
Reseating the memory modules (see Installing Memory
see "Contacting Dell" in your Owner's Manual for instructions on obtaining technical assistance.
CodeCause
1-3-1 through 2-4-4 Memory not being properly identified or used
4-3-1Memory failure above address 0FFFFh
If you experience any of the following non-memory related beep code errors, see "Contacting Dell" in your Owner's Manual
for instructions on obtaining technical assistance.
Advanced Troubleshooting: Dell Dimension E520 Service Manual
State Low
3-1-1 Slave DMA register failure
3-1-2 Master DMA register failure
3-1-3 Master interrupt mask register failure
3-1-4 Slave interrupt mask register failure
3-2-2 Interrupt vector loading failure
3-2-4 Keyboard Controller Test failure
3-3-1 NVRAM power loss
3-3-2 NVRAM configuration
3-3-4 Video Memory Test failure
3-4-1 Screen initialization failure
3-4-2 Screen retrace failure
3-4-3 Search for video ROM failure
4-2-1 No time tick
4-2-2 Shutdown failure
4-2-3 Gate A20 failure
4-2-4 Unexpected interrupt in protected mode
4-3-3 Timer-chip counter 2 failure
4-3-4 Time-of-day clock stopped
4-4-1 Serial or parallel port test failure
4-4-4 Cache test failure
System Messages
NOTE: If the message you received is not listed in the table, see the documentation for either the operating system or
the program that was running when the message appeared.
MessagePossible CauseCorrective Action
8042 GateA20 error
Address Line
Short!
C: Drive
Error
C: Drive
Failure
Cache
Memory Bad,
Do Not
Enable
Cache
CH-2 Timer
Error
CMOS Battery
The keyboard controller
failed its test.
An error in the address
decoding circuitry in the
memory has occurred.
The hard drive is not
working or is not
configured correctly.
The cache memory is not
operating.
An error is occurring on
the timer on the system
board.
The system configurationEnter the system setup program (see Entering
If you receive this message after you make changes
in the system setup program, enter the system
setup program (see Entering System Setup
restore the original value(s).
Reseat the memory modules (see Memory
Ensure that the drive is installed correctly in the
computer and defined correctly in the system setup
program (see Entering System Setup
See "Contacting Dell" in your Owner's Manual for
instructions on obtaining technical assistance.
See "Contacting Dell" in your Owner's Manual for
instructions on obtaining technical assistance.
Advanced Troubleshooting: Dell Dimension E520 Service Manual
information in the system
System Setup), verify the system configuration,
CMOS
Checksum
Failure
CMOS System
Options Not
Set
CMOS Display
Type
Mismatch
CMOS Memory
Size
Mismatch
CMOS Time
and Date Not
Set
Diskette
Boot Failure
DMA Error
DMA 1 Error
DMA 2 Error
FDD
Controller
Failure
HDD
Controller
Failure
INTR1 Error
INTR2 Error
Invalid Boot
Diskette
Keyboard
Error
KB/Interface
Error
No ROM
Basic
setup program is incorrect
or the battery charge may
be low.
Drive A or B is present
but has failed the BIOS
POST.
Error in the DMA
controller on the system
board.
The BIOS cannot
communicate with the
floppy drive or hard drive
controller.
An interrupt channel on
the system board failed to
POST.
The operating system
cannot be located on drive
A or drive C.
The BIOS has detected a
stuck key.
An error occurred with the
keyboard connector.
The operating system
cannot be located on drive
A or drive C.
and then restart the computer.
Ensure that the drive is installed correctly in the
computer and defined correctly in the system setup
program (see Entering System Setup
interface cable at both ends.
The keyboard or system board may need to be
replaced.
Ensure that the floppy drive or the hard drive is
installed correctly in the computer (see Drives
defined correctly in the system setup program (see
Entering System Setup
at both ends.
The keyboard or system board may need to be
replaced.
Enter the system setup program (see Entering
System Setup)and confirm that drive A or drive C
is properly identified.
Ensure that nothing is resting on the keyboard; if a
key appears to be stuck, carefully pry it up. If the
problem persists, you may need to replace the
keyboard.
Ensure that nothing is resting on the keyboard; if a
key appears to be stuck, carefully pry it up. If the
problem persists, you may need to replace the
keyboard.
Enter the system setup program (see Entering
System Setup) and confirm that drive A or drive C
is properly identified.
). Check the interface cable
). Check the
) and
Dell Diagnostics
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the
Product Information Guide.
NOTE: The Dell Diagnostics only operate on Dell computers.
Advanced Troubleshooting: Dell Dimension E520 Service Manual
2. When the DELL logo appears, press <F12> immediately.
3. At the Boot Device Menu, use the up- and down-arrow keys or press the appropriate number on the keyboard to
4. At the Dell Diagnostics Main Menu, left-click with the mouse, or press <Tab> and then <Enter>, to select the test you
5. After all tests have completed, close the test window to return to the Dell Diagnostics MainMenu.
6. Close the Main Menu window to exit the Dell Diagnostics and restart the computer.
NOTE: Keyboard failure may result when a key is held down for extended periods of time. To avoid possible
keyboard failure, press and release <F12> in even intervals to open the Boot Device Menu.
If you wait too long and the operating system logo appears, continue to wait until you see the Microsoft® Windows®
desktop, then shut down your computer and try again.
highlight Boot to Utility Partition, and then press <Enter>.
NOTE: The Quickboot feature changes the boot sequence for the current boot only. Upon restart, the computer
boots according to the boot sequence specified in system setup.
want to run (see Dell Diagnostics Main Menu
NOTE: Write down any error codes and problem descriptions exactly as they appear and follow the instructions
on the screen.
).
Dell Diagnostics Main Menu
The following tests can be run from the Dell Diagnostics Main Menu:
OptionFunction
Express
Test
Extended
Test
Custom
Test
Symptom
Tree
For any problem encountered during a test, a message appears with an error code and a description of the problem. Write
down the error code and problem description exactly as it appears and follow the instructions on the screen. If you cannot
resolve the problem, see "Contacting Dell" in your Owner's Manual for instructions on obtaining technical assistance.
NOTE: The Service Tag for your computer is located at the top of each test screen. When contacting Dell support, have
your Service Tag ready.
The following tabs provide additional information for tests run from the Custom Test or Symptom Tree option:
Performs a quick test of system devices. The test typically takes 10 to 20 minutes and requires no interaction on
your part. Run Express Test first to increase the possibility of tracing the problem quickly.
Performs a thorough check of system devices. The test typically takes an hour or more and peridocially requires
your input to answer specific questions.
Tests a specific device in the system and can be used to customize the tests you want to run.
Lists a number of common symptoms and allows you to select a test based on the symptom of the problem you
are having.
TabFunction
ResultsDisplays the results of the test and any error conditions encountered.
ErrorsDisplays error conditions encountered, error codes, and the problem description.
HelpDescribes the test and any requirements for running the test.
ConfigurationDisplays the hardware configuration for the selected device.
Advanced Troubleshooting: Dell Dimension E520 Service Manual
(Custom
Test
only)
Parameters
(Custom
Test
only)
The Dell Diagnostics obtains configuration information for all devices from system setup, memory, and
various internal tests, and it displays the information in the device list in the left pane of the screen.
NOTE: The device list may not display the names of all the components installed on your computer or all
devices attached to your computer.
Allows you to customize the test, if applicable, by changing the test settings.
Drivers
What Is a Driver?
A driver is a program that controls a device such as a printer, mouse, or keyboard. All devices require a driver program.
A driver acts as a translator between the device and any other programs that use the device. Each device has its own set of
specialized commands that only the driver for that device recognizes.
Required drivers are already installed on your computer—no further installation or configuration is needed.
®
Many drivers, such as the keyboard driver, come with your Microsoft
drivers if you:
Upgrade your operating system.
Reinstall your operating system.
Connect or install a new device.
Windows® operating system. You may need to install
Identifying Drivers
If you experience a problem with any device, identify whether the driver is the source of your problem and, if necessary,
update the driver.
Windows XP
1. Click the Start button, then click Control Panel.
2. Under Pick a Category, click Performance and Maintenance.
3. Click System.
4. In the System Properties window, click the Hardware tab.
5. Click Device Manager.
6. Scroll down the list of devices and check for an exclamation point (a circle with a [!]) next to the device name.
If an exclamation point appears next to the device name, you may need to reinstall the driver or install a new driver.