HP dx7400 - Microtower PC User Manual

Small Form Factor (SFF)
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.
Generating Static
The following table shows that:
●
Different activities generate different amounts of static electricity.
●
Static electricity increases as humidity decreases.
Relative Humidity
Event
55% 40% 10%
Walking across carpet
Walking across vinyl floor
Motions of bench worker
Removing DIPs* from plastic tube
7,500 V
3,000 V
400 V
400 V
15,000 V
5,000 V
800 V
700 V
35,000 V
12,000 V
6,000 V
2,000 V
Removing DIPs* from vinyl tray
Removing DIPs* from Styrofoam
Removing bubble pack from PCB
2,000 V
3,500 V
7,000 V
4,000 V
5,000 V
20,000 V
11,500 V
14,500 V
26,500 V
Electrostatic Discharge Information 49

HP dx7400 - Microtower PC Specifications

General

Brand	HP
Model	dx7400 - Microtower PC
Category	Desktop
Language	English