[ Pobierz całość w formacie PDF ]
loop back plugs
3.14 Documentation
Table 3-16
Spare Parts: Documentation
Description Spare Part Number
Compaq ArmadaStation and Armada MiniStation Maintenance & Service Guide 296390-001
Compaq ArmadaStation and Armada MiniStation Illustrated Parts Map 296391-001
Compaq ArmadaStation and Armada MiniStation Installation and Operations Guide
(both guides included in spare kit)
Dutch 296691-331 Italian 296691-061
English 296691-001 Japanese 296691-291
French 296691-051 Latin American Spanish 296691-161
German 296691-041 Swedish 296691-101
3-18 Illustrated Parts Catalog
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 4
Removal and Replacement Preliminaries
This chapter provides general service information for the Compaq ArmadaStation and
Armada MiniStation. Adherence to the procedures and precautions described in this
chapter is essential for proper service.
4.1 Electrostatic Discharge
A sudden discharge of static electricity from a 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 will 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.
Generating Static
Table 4-1 shows how different activities generate static electricity and 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 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
NOTE: 700 volts can degrade a product.
Removal and Replacement Preliminaries 4-1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preventing Electrostatic Damage to Equipment
Many electronic components are sensitive to ESD. Circuitry design and structure
determine the degree of sensitivity. The following proper packaging and ground
precautions are necessary to prevent damage.
Protect all electrostatic sensitive parts and assemblies with nonconductive or
approved containers or packaging.
Keep electrostatic sensitive parts in their containers until they arrive at static-free
stations.
Place items on a grounded surface before removing them from their container.
Always be properly grounded when touching a sensitive component or assembly.
Place reusable electrostatic-sensitive parts from assemblies in protective
packaging or nonconductive foam.
Use transporters and conveyers made of antistatic belts and roller bushings. Mechanized
equipment used for moving materials must be wired to ground and proper materials
selected to avoid static charging. When grounding is not possible, use an ionizer to
dissipate electric charges.
Preventing Damage to Drives
To prevent static damage to drives, follow these precautions:
Handle drives gently, using static-guarding techniques.
Store drives in the hard drive carrying case. Do not use the MultiBay device
carrying case.
Avoid dropping drives from any height onto any surface.
Handle drives on surfaces that have at least one inch of shock-proof foam.
Avoid touching the connectors on the hard drive.
4-2 Removal and Replacement Preliminaries
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Grounding Methods
The method for grounding must include either a wrist strap or a foot strap at a grounded
workstation. When seated, wear a wrist strap connected to a grounded system. When
standing, use footstraps and a grounded floor mat.
Table 4-2
Static Shielding Protection Levels
Method Voltage
Antistatic plastic 1,500 V
Carbon-loaded plastic 7,500 V
Metallized laminate 15,000 V
Grounding Workstations
To prevent static damage at the workstation, follow these precautions:
[ Pobierz całość w formacie PDF ]