HP 20-k127cl Mobile manual Component replacement procedures, Material Use Voltage protection level

Equipment guidelines

Grounding equipment must include either a wrist strap or a foot strap at a grounded workstation.

●When seated, wear a wrist strap connected to a grounded system. Wrist straps are flexible straps with a minimum of one megohm ±10% resistance in the ground cords. To provide proper ground, wear a strap snugly against the skin at all times. On grounded mats with banana-plug connectors, use alligator clips to connect a wrist strap.

●When standing, use foot straps and a grounded floor mat. Foot straps (heel, toe, or 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 foot straps on both feet with a minimum of one megohm resistance between the operator and ground. To be effective, the conductive must be worn in contact with the skin.

The following grounding equipment is recommended to prevent electrostatic damage:

●Antistatic tape

●Antistatic smocks, aprons, and sleeve protectors

●Conductive bins and other assembly or soldering aids

●Nonconductive foam

●Conductive tabletop workstations with ground cords of one megohm resistance

●Static-dissipative tables or floor mats with hard ties to the ground

●Field service kits

●Static awareness labels

●Material-handling packages

●Nonconductive plastic bags, tubes, or boxes

●Metal tote boxes

●Electrostatic voltage levels and protective materials

The following table lists the shielding protection provided by antistatic bags and floor mats.

Material	Use	Voltage protection level
Antistatic plastics	Bags	1,500 V
Carbon-loaded plastic	Floor mats	7,500 V
Metallized laminate	Floor mats	5,000 V

Component replacement procedures

CAUTION: Components described in this chapter should only be accessed by an authorized service provider. Accessing these parts can damage the computer or void the warranty.

This chapter provides removal and replacement procedures for Authorized Service Provider only parts.

There are as many as 82 screws that must be removed, replaced, and/or loosened when servicing the computer. Make special note of each screw size and location during removal and replacement.

22 Chapter 4 Removal and replacement procedures