Maintenance &
Service Guide
Presario 1200 Series
Models: 1255, 1257, 1260, 1262, 1266, and 1267
| Home
Page | Notice | Preface | Product
Description | Troubleshooting
Illustrated Parts Catalog | Removal & Replacement Procedures | Specifications
Pin Assignments | Battery
Pack Operations
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 an 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, it is possible for the exposed
device's internal layers to degrade, reducing its life expectancy considerably.
Networks built into multiple
integrated circuits provide some protection, but in many cases, the discharge can contain
enough power to alter device parameters and melt silicon junctions.
|
Generating Static
This table shows the
different electrostatic voltage levels generated by various activities .
NOTE:
700 volts can degrade a product. |
Typical Electrostatic
Voltages |
Event |
Relative Humidity |
10% |
40% |
55% |
Walking across
carpet |
35,000 V |
15,000 V |
7,500 V |
Walking across
vinyl floor |
12,000 V |
5,000 V |
3,000 V |
Motions of bench
worker |
6,000 V |
800 V |
400 V |
Removing DIPS
from plastic tubes |
2,000 V |
700 V |
400 V |
Removing DIPS
from vinyl trays |
11,500 V |
4,000 V |
2,000 V |
Removing DIPS
from Styrofoam |
14,500 V |
5,000 V |
3,500 V |
Removing bubble
pack from PCBs |
26,000 V |
20,000 V |
7,000 V |
Packing PCBs in
foam-lined box |
21,000 V |
11,000 V |
5,000 V |
Return to Removal & Replacement
Procedures
|