Compaq XL183 - Manual (Page 70)

P RESARIO N OTEBOOK M AINTENANCE AND S ERVICE G UIDE 1800 S ERIES R EMOVAL AND R EPLACEMENT 1
Presario 1800 Series
Models: XL180, XL181, XL182, XL183, XL185,
and XL190, XL191, XL192
Removal and Replacement
This chapter details removing and replacing each component of the Presario 1800XL
Notebook Computers.
Electrostatic Discharge
When removing or replacing parts, be careful to discharge static electricity before touching
the Notebook’s internal components. A sudden discharge of static electricity from a finger
or other conductor can destroy static-sensitive devices and microcircuitry. Often the spark
is neither felt nor heard, but damage occurs. An electronic device exposed to an
electrostatic discharge may not seem affected and work perfectly throughout a normal
cycle. However, the discharge degrades internal layers, which reduces the operating life of
the device. 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.
The table below shows the amount of static electricity generated by common activities
associated with servicing computers.
Ä CAUTION: As little as 700 Volts can degrade Notebook components. Be sure to
ground yourself before touching the Notebook or its subassemblies.
Generated Electrostatic Voltage
Activity
Relative Humidity
10%
40% 50%
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