Dell Inspiron 5400 AIO Inspiron 24-5400 Service Manual - Page 7

Electrostatic discharge—ESD protection, ESD field service kit

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5. Remove any media card and optical disc from your computer, if applicable. 6. After the computer is unplugged, press and hold the power button for 5 seconds to ground the system board. CAUTION: Place the computer on a flat, soft, and clean surface to avoid scratches on the display. 7. Place the computer face down. 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 For this reason, some previously approved methods of handling parts are no longer applicable.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. 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 Safety instructions 7

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5.
Remove any media card and optical disc from your computer, if applicable.
6.
After the computer is unplugged, press and hold the power button for 5 seconds to ground the system board.
CAUTION:
Place the computer on a flat, soft, and clean surface to avoid scratches on the display.
7.
Place the computer face down.
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.
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
Safety instructions
7