62 REMOVAL AND REPLACEMENT PROCEDURES
Service Considerations
The following sections discuss service considerations that should be reviewed and practiced before
removing and replacing any system components.
WARNING! When lifting or moving the workstation, do not use the front bezel as a handle or lifting point.
Lifting the workstation from the front bezel or lifting it incorrectly can cause the unit to fall and harm the
user and damage the workstation. To properly and safely lift the workstation, lift it from the bottom of the
unit.
Read Cautions, Warnings and Safety Precautions
For your safety, you must review the “Important Safety Warnings” on page ix before accessing the
components of the workstation. Also, review the
Safety and Regulatory Guide
that came with your
workstation for more information.
WARNING!
Avoid Burn Injuries.
Some parts inside the computer will be hot. Turn off and unplug the
system, then wait approximately three to five minutes for them to cool down before opening the system
access panels or touching internal components.
Electrostatic Discharge Information
A sudden discharge of static electricity from your 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 electrostatic discharge (ESD) might not appear to be affected at all and can work
perfectly throughout a normal cycle. The device can function normally for a while, but it has 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 following table shows that:
Different activities generate different amounts of static electricity.
Static electricity increases as humidity decreases.
Table 4-1 Static Electricity
Relative Humidity
Event 55% 40% 10%
Walking across carpet
Walking across vinyl floor
Motions of bench worker
7,500 V
3,000 V
400 V
15,000 V
5,000 V
800 V
35,000 V
12,000 V
6,000 V
Removing bubble pack from PCB
Packing PCBs in foam-lined box
7,000 V
5,000 V
20,000 V
11,000 V
26,500 V
21,000 V
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