Maintenance
& Service Guide
Presario 1200 Series
Models: 1255, 1256, 1260, 1262, 1266, 1267, 1272, 1273, 1274, and 1275
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Electrostatic Discharge

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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.
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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
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