ESD is a major concern when you handle electronic components, especially sensitive components such as expansion cards, processors, memory modules, and system boards. A slight charge 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.
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 module that has received a static shock and immediately generates a "No POST/No Video" symptom with a beep code that is 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 memory module receives a static shock, but the tracing is merely weakened and does not immediately produce outward symptoms that are 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, and so on.
Intermittent failures that are also called latent or "walking wounded" are difficult to detect and troubleshoot.
Perform the following steps to prevent ESD damage:
Use a wired ESD wrist strap that is properly grounded. Wireless anti-static straps 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, use the anti-static wrist strap to
discharge the static electricity from your body.
NOTE:You can protect against ESD and discharge static electricity from your
body by touching a metal-grounded object before you interact with
anything electronic, for example, an unpainted metal surface on your
computer’s I/O panel. When connecting a peripheral (including handheld
digital assistants) to your computer, you should always ground both
yourself and the peripheral before connecting it to the computer. In
addition, as you work inside the computer, periodically touch a
metal-grounded object to remove any static charge that your body may
have accumulated.