HP 14XL250, 14XL352, 14XL355, 14XL246, 14XL242 manual Electrostatic Discharge

Presario 1400 Series

Model XL240, XL241, XL242, XL244, XL245, XL246, XL247, XL250, XL340, XL341, XL342, XL343, XL344, XL345, XL346, XL350, XL352, XL355, and XL356

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 that has been exposed to electrostatic discharge (ESD) may not seem to be affected and work perfectly throughout a normal cycle. Although it may function normally for a period of time, it may have 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 table below shows activities that generate static electricity and their associated level of electrostatic voltage.

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

Note: 700 volts can degrade a product.

PRESARIO NOTEBOOK MAINTENANCE AND SERVICE GUIDE 1400 SERIES REMOVAL SEQUENCE 17