HP Compaq Compaq dx2290, Руководство по обслуживанию и справочник

Страница: 28 / 81

5 Identifying the Chassis, Routine Care,
and Disassembly Preparation
This chapter provides general service information for the computer. Adherence to the procedures and
precautions described in this chapter is essential for proper service.
CAUTION: When the computer is plugged into an AC power source, voltage is always applied to the
system board. You must disconnect the power cord from the power source before opening the computer
to prevent system board or component damage.
Chassis Designations
The following subsection illustrates the dx2290 chassis design.
Microtower (MT)
Electrostatic Discharge Information
A sudden discharge of static electricity from your finger or other conductor can destroy static-sensitive
devices or microcircuitry. Often the spark is neither felt nor heard, but damage occurs. An electronic
device exposed to electrostatic discharge (ESD) may not appear to be affected at all and can work
perfectly throughout a normal cycle. The device may function normally for a while, but it has been
degraded in the internal layers, reducing its life expectancy.
Networks built into many integrated circuits provide some protection, but in many cases, the discharge
contains enough power to alter device parameters or melt silicon junctions.
20 Chapter 5 Identifying the Chassis, Routine Care, and Disassembly Preparation