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 nonmetal 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 For this reason, some previously approved methods of handling parts are no longer applicable.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.
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 in 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, be sure 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
10
Working on your computer
Summary of Contents for Inspiron 5720
Page 1: ...Precision 5720 All in One Owner s Manual Regulatory Model W13C Regulatory Type W13C001 ...
Page 69: ...2 Place the middle frame on the assembly Removing and installing components 69 ...
Page 86: ...86 Technology and components ...
Page 97: ...Software 97 ...
Page 100: ...100 Software ...
Page 106: ...106 Troubleshooting ...