Removal And Replacement; Electrostatic Discharge - Compaq Presario,Presario 18XL191 User Manual

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.
Activity
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
Ä
CAUTION: As little as 700 Volts can degrade Notebook components. Be sure to
ground yourself before touching the Notebook or its subassemblies.
P N M
RESARIO OTEBOOK AINTENANCE AND
Presario 1800 Series
Models: XL180, XL181, XL182, XL183, XL185,
and XL190, XL191, XL192
Generated Electrostatic Voltage
S G 1800 S
ERVICE UIDE ERIES
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
26,000 V 20,000 V
21,000 V 11,000 V
50%
7,500 V
3,000 V
400 V
400 V
2,000 V
3,500 V
7,000 V
5,000 V
R R
EMOVAL AND EPLACEMENT
1