Compaq Deskpro 2000
4-1
chapter
4
R
EMOVAL AND
R
EPLACEMENT
P
RELIMINARIES
This chapter provides general service information for the computer. Adherence to the procedures and
precautions described in this chapter is essential for proper service.
4.1 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) may not be affected at all and can work perfectly
throughout a normal cycle. Or it may function normally for a while, then degrade 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.
4.1.1
Generating Static
Table 4-1 shows how different activities generate static electricity at different electrostatic voltage
levels.
Table 4-1
Typical Electrostatic Voltages
Relative Humidity
Event
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 tube
2,000 V
700 V
400 V
Removing DIPs* from vinyl tray
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 PCB
26,500 V
20,000 V
7,000 V
Packing PCBs in foam-lined box
21,000 V
11,000 V
5,000 V
*Dual Inline Packaging (DIP) is the packaging around individual microcircuitry. These are then multi-packaged inside plastic tubes, trays,
or Styrofoam.
✎
700 volts can degrade a product
.
Содержание Deskpro 2000 Series
Страница 1: ...MAINTENANCE SERVICE GUIDE COMPAQ DESKPRO 2000 SERIES OF PERSONAL COMPUTERS...
Страница 2: ...243064 001 243211 001...
Страница 4: ...CPS...
Страница 30: ...1 18 Product Description 1 5 1 Front Panel Lights and Controls Figure 1 5 Power Switch and Front Panel Lights...
Страница 32: ...1 20 Product Description Figure 1 6 Drive Positions on the Minitower Computer...
Страница 34: ...1 22 Product Description Figure 1 7 Rear Panel Connectors...
Страница 82: ...3 2 Illustrated Parts Catalog 3 1 System Unit Figure 3 2 System Unit Desktop...
Страница 84: ...3 4 Illustrated Parts Catalog Figure 3 3 System Unit Minitower...
Страница 86: ...3 6 Illustrated Parts Catalog 3 2 Mass Storage Devices Figure 3 4 Mass Storage Devices...
Страница 88: ...3 8 Illustrated Parts Catalog 3 3 Cables Figure 3 5 Cables...
Страница 90: ...3 10 Illustrated Parts Catalog 3 4 Standard and Optional Boards Figure 3 6 Standard and Optional Boards...
Страница 96: ...3 16 Illustrated Parts Catalog 3 6 Monitors Figure 3 9 Monitors...
