HP Compaq SP750, Руководство по техническому обслуживанию и ремонту

Страница: 37 / 132

Removal and Replacement Preliminaries 3-3
Personal Grounding Methods and Equipment
Use the following equipment to prevent static electricity damage to equipment:
■ Wrist straps are flexible straps with a minimum of one-/- 10 percent resistance
in the ground cords. To provide proper ground, a strap must be worn snug against bare
skin. The ground cord must be connected and fit snugly into the banana plug connector on
the grounding mat or workstation.
■ Heel straps/Toe straps/Boot straps can be used at standing workstations and are
compatible with most types of shoes or boots. On conductive floors or dissipative floor
mats, use them on both feet with a minimum of one-/- 10 percent resistance
between the operator and ground.
Table 3-2
Static Shielding Protection Levels
Method Voltage
Antistatic plastic 1,500
Carbon-loaded plastic 7,500
Metallized laminate 15,000
Grounding Workstations
To prevent static damage at the workstation, use the following precautions:
■ Cover the workstation with approved static-dissipative material. Provide a wrist strap
connected to the work surface and properly grounded tools and equipment.
■
Use static-dissipative mats, foot straps, or air ionizers to give added protection.
■ Handle electrostatic sensitive components, parts, and assemblies by the case or PCB
laminate. Handle them only at static-free workstations.
■
Turn off power and input signals before inserting and removing connectors or test
equipment.
■ Use fixtures made of static-safe materials when fixtures must directly contact dissipative
surfaces.
■
Keep work area free of nonconductive materials such as ordinary plastic assembly aids
and Styrofoam.
■ Use field service tools, such as cutters, screwdrivers, and vacuums, that are conductive.