Removal And Replacement Procedures; Generating Static - Compaq Presario 305 Maintenance And Service Manual

Compaq Presario Series Maintenance and Service Guide
Before You Begin
Removal Sequence
Product Description

Removal and Replacement Procedures

Electrostatic Discharge
A sudden discharge of static electricity from a 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 be affected at all and will work
perfectly throughout a normal cycle. Although, it may function normally for a
while, then degrade 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 table shows how different activities generate static electricity and at
different electrostatic voltage levels.
Event
Walking across carpet
Walking across vinyl floor
Motions of bench worker
Removing DIPS from plastic tubes
Removing DIPS from vinyl trays
Removing DIPS from Styrofoam
Removing bubble pack from PCBs
Packing PCBs in foam-lined box
NOTE: 700 volts can degrade a
product.
Material
Antistatic Plastic
Carbon-loaded plastic Floor mats
Metallized laminate
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Presario 305 Model
Specifications
Troubleshooting
Pin Assignments
Typical Electrostatic Voltages
Static-Shielding Materials
Use
Bags
Floor mats
United States
Relative Humidity
10% 40%
35,000 V 15,000 V
12,000 V 5,000 V
6,000 V 800 V
2,000 V 700 V
11,500 V 4,000 V
14,500 V 5,000 V
26,500 V 20,000 V
21,000 V 11,000 V
Voltage Protection Level
1,500 V
7,500 V
15,000 V
December 9, 2002
Parts Catalog
Battery Operations
Index
55%
7,500 V
3,000 V
400 V
400 V
2,000 V
3,500 V
7,000 V
5,000 V