Removal Sequence; Electrostatic Discharge - Compaq 12XL125 - Presario - K6-2 533 MHz Maintenance & Service Manual

Removal Sequence

This chapter provides details for removing and replacing each component of the Presario
1200XL units.

Electrostatic Discharge

When removing or replacing parts, be careful to discharge static electricity before touching
the internal Notebook 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 to be affected and continue to 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.
Event
Walking across carpet
Walking across vinyl floor
Motion 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 1200XL Series
Model XL300, XL300A, and XL300B
Electrostatic Voltage
S G 1200XL 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 S 1
EMOVAL EQUENCE