Dell Vostro 3890 User manual

Vostro 3890
Service Manual
Regulatory Model: D29M
Regulatory Type: D29M004
April 2021
Rev. A00

Notes, cautions, and warnings
NOTE: A NOTE indicates important information that helps you make better use of your product.
CAUTION: A CAUTION indicates either potential damage to hardware or loss of data and tells you how to avoid
the problem.
WARNING: A WARNING indicates a potential for property damage, personal injury, or death.
© 2021 Dell Inc. or its subsidiaries. All rights reserved. Dell, EMC, and other trademarks are trademarks of Dell Inc. or its subsidiaries. Other
trademarks may be trademarks of their respective owners.

Working inside your computer
Safety instructions
Use the following safety guidelines to protect your computer from potential damage and to ensure your personal safety. Unless
otherwise noted, each procedure included in this document assumes that you have read the safety information that shipped
with your computer.
WARNING: Before working inside your computer, read the safety information that is shipped with your
computer. For more safety best practices, see the Regulatory Compliance home page at www.dell.com/
regulatory_compliance.
WARNING: Disconnect your computer from all power sources before opening the computer cover or panels.
After you finish working inside the computer, replace all covers, panels, and screws before connecting your
computer to an electrical outlet.
CAUTION: To avoid damaging the computer, ensure that the work surface is flat, dry, and clean.
CAUTION: To avoid damaging the components and cards, handle them by their edges, and avoid touching the
pins and the contacts.
CAUTION: You should only perform troubleshooting and repairs as authorized or directed by the Dell technical
assistance team. Damage due to servicing that is not authorized by Dell is not covered by your warranty. See the
safety instructions that is shipped with the product or at www.dell.com/regulatory_compliance.
CAUTION: 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 static electricity which could harm internal components.
CAUTION: When you disconnect a cable, pull it by its connector or its pull tab, not the cable itself. Some cables
have connectors with locking tabs or thumbscrews that you must disengage before disconnecting the cable.
When disconnecting cables, keep them evenly aligned to avoid bending the connector pins. When connecting
cables, ensure that the ports and the connectors are correctly oriented and aligned.
CAUTION: Press and eject any installed card from the media-card reader.
NOTE: The color of your computer and certain components may appear differently than shown in this document.
Before working inside your computer
About this task
NOTE: The images in this document may differ from your computer depending on the configuration you ordered.
Steps
1. Save and close all open files and exit all open applications.
2. Shut down your computer. Click Start > Power > Shut down.
NOTE: If you are using a different operating system, see the documentation of your operating system for shut-down
instructions.
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Working inside your computer 3

3. Disconnect your computer and all attached devices from their electrical outlets.
4. Disconnect all attached network devices and peripherals, such as keyboard, mouse, and monitor from your computer.
CAUTION: To disconnect a network cable, first unplug the cable from your computer and then unplug the
cable from the network device.
5. Remove any media card and optical disc from your computer, if applicable.
Safety precautions
The safety precautions chapter details the primary steps to be taken before performing any disassembly instructions.
Observe the following safety precautions before you perform any installation or break/fix procedures involving disassembly or
reassembly:
●Turn off the system and all attached peripherals.
●Disconnect the system and all attached peripherals from AC power.
●Disconnect all network cables, telephone, and telecommunications lines from the system.
●Use an ESD field service kit when working inside any tabletnotebookdesktop to avoid electrostatic discharge (ESD) damage.
●After removing any system component, carefully place the removed component on an anti-static mat.
●Wear shoes with non-conductive rubber soles to reduce the chance of getting electrocuted.
Standby power
Dell products with standby power must be unplugged before you open the case. Systems that incorporate standby power are
essentially powered while turned off. The internal power enables the system to be remotely turned on (wake on LAN) and
suspended into a sleep mode and has other advanced power management features.
Unplugging, pressing and holding the power button for 20 seconds should discharge residual power in the system board.
Remove the battery from tablets.notebooks.
Bonding
Bonding is a method for connecting two or more grounding conductors to the same electrical potential. This is done through
the use of a field service electrostatic discharge (ESD) kit. When connecting a bonding wire, ensure that it is connected to bare
metal and never to a painted or non-metal surface. The wrist strap should be secure and in full contact with your skin, and
ensure that you remove all jewelry such as watches, bracelets, or rings prior to bonding yourself and the equipment.
Electrostatic discharge—ESD protection
ESD is a major concern when you handle electronic components, especially sensitive components such as expansion cards,
processors, memory DIMMs, and system boards. Very slight charges can damage circuits in ways that may not be obvious, such
as intermittent problems or a shortened product life span. As the industry pushes for lower power requirements and increased
density, ESD protection is an increasing concern.
Due to the increased density of semiconductors used in recent Dell products, the sensitivity to static damage is now higher than
in previous Dell products. For this reason, some previously approved methods of handling parts are no longer applicable.
Two recognized types of ESD damage are catastrophic and intermittent failures.
●Catastrophic – Catastrophic failures represent approximately 20 percent of ESD-related failures. The damage causes
an immediate and complete loss of device functionality. An example of catastrophic failure is a memory DIMM that has
received a static shock and immediately generates a "No POST/No Video" symptom with a beep code emitted for missing or
nonfunctional memory.
●Intermittent – Intermittent failures represent approximately 80 percent of ESD-related failures. The high rate of
intermittent failures means that most of the time when damage occurs, it is not immediately recognizable. The DIMM
receives a static shock, but the tracing is merely weakened and does not immediately produce outward symptoms related to
the damage. The weakened trace may take weeks or months to melt, and in the meantime may cause degradation of memory
integrity, intermittent memory errors, etc.
The more difficult type of damage to recognize and troubleshoot is the intermittent (also called latent or "walking wounded")
failure.
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Perform the following steps to prevent ESD damage:
●Use a wired ESD wrist strap that is properly grounded. The use of wireless anti-static straps is no longer allowed; they do not
provide adequate protection. Touching the chassis before handling parts does not ensure adequate ESD protection on parts
with increased sensitivity to ESD damage.
●Handle all static-sensitive components in a static-safe area. If possible, use anti-static floor pads and workbench pads.
●When unpacking a static-sensitive component from its shipping carton, do not remove the component from the anti-static
packing material until you are ready to install the component. Before unwrapping the anti-static packaging, ensure that you
discharge static electricity from your body.
●Before transporting a static-sensitive component, place it in an anti-static container or packaging.
ESD field service kit
The unmonitored Field Service kit is the most commonly used service kit. Each Field Service kit includes three main components:
anti-static mat, wrist strap, and bonding wire.
Components of an ESD field service kit
The components of an ESD field service kit are:
●Anti-Static Mat – The anti-static mat is dissipative and parts can be placed on it during service procedures. When using an
anti-static mat, your wrist strap should be snug and the bonding wire should be connected to the mat and to any bare metal
on the system being worked on. Once deployed properly, service parts can be removed from the ESD bag and placed directly
on the mat. ESD-sensitive items are safe in your hand, on the ESD mat, in the system, or inside a bag.
●Wrist Strap and Bonding Wire – The wrist strap and bonding wire can be either directly connected between your wrist
and bare metal on the hardware if the ESD mat is not required, or connected to the anti-static mat to protect hardware that
is temporarily placed on the mat. The physical connection of the wrist strap and bonding wire between your skin, the ESD
mat, and the hardware is known as bonding. Use only Field Service kits with a wrist strap, mat, and bonding wire. Never
use wireless wrist straps. Always be aware that the internal wires of a wrist strap are prone to damage from normal wear
and tear, and must be checked regularly with a wrist strap tester in order to avoid accidental ESD hardware damage. It is
recommended to test the wrist strap and bonding wire at least once per week.
●ESD Wrist Strap Tester – The wires inside of an ESD strap are prone to damage over time. When using an unmonitored
kit, it is a best practice to regularly test the strap prior to each service call, and at a minimum, test once per week. A
wrist strap tester is the best method for doing this test. If you do not have your own wrist strap tester, check with your
regional office to find out if they have one. To perform the test, plug the wrist-strap's bonding-wire into the tester while it is
strapped to your wrist and push the button to test. A green LED is lit if the test is successful; a red LED is lit and an alarm
sounds if the test fails.
●Insulator Elements – It is critical to keep ESD sensitive devices, such as plastic heat sink casings, away from internal parts
that are insulators and often highly charged.
●Working Environment – Before deploying the ESD Field Service kit, assess the situation at the customer location. For
example, deploying the kit for a server environment is different than for a desktop or portable environment. Servers are
typically installed in a rack within a data center; desktops or portables are typically placed on office desks or cubicles. Always
look for a large open flat work area that is free of clutter and large enough to deploy the ESD kit with additional space to
accommodate the type of system that is being repaired. The workspace should also be free of insulators that can cause an
ESD event. On the work area, insulators such as Styrofoam and other plastics should always be moved at least 12 inches or
30 centimeters away from sensitive parts before physically handling any hardware components
●ESD Packaging – All ESD-sensitive devices must be shipped and received in static-safe packaging. Metal, static-shielded
bags are preferred. However, you should always return the damaged part using the same ESD bag and packaging that the
new part arrived in. The ESD bag should be folded over and taped shut and all the same foam packing material should be
used in the original box that the new part arrived in. ESD-sensitive devices should be removed from packaging only at an
ESD-protected work surface, and parts should never be placed on top of the ESD bag because only the inside of the bag is
shielded. Always place parts in your hand, on the ESD mat, in the system, or inside an anti-static bag.
●Transporting Sensitive Components – When transporting ESD sensitive components such as replacement parts or parts
to be returned to Dell, it is critical to place these parts in anti-static bags for safe transport.
ESD protection summary
It is recommended that all field service technicians use the traditional wired ESD grounding wrist strap and protective anti-static
mat at all times when servicing Dell products. In addition, it is critical that technicians keep sensitive parts separate from all
insulator parts while performing service and that they use anti-static bags for transporting sensitive components.
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