Maintenance and Service Guide

4

Removal and Replacement

Preliminaries

This chapter provides essential information for proper and safe removal and replacement service.

4.1 Tools Required

You will need the following tools to complete the removal and replacement procedures:

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Magnetic screwdriver

Phillips P0 screwdriver

Torx T8 screwdriver

5.0-mm socket for system board locks

Flat-bladed screwdriver

Tool kit—includes connector removal tool, loopback plugs, and case utility tool

Maintenance and Service Guide 4–1

Removal and Replacement Preliminaries

4.2 Service Considerations

The following sections include some of the considerations that you should keep in mind during disassembly and assembly procedures.

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As you remove each subassembly from the notebook, place the subassembly (and all accompanying screws) away from the work area to prevent damage.

Plastic Parts

Using excessive force during disassembly and reassembly can damage plastic parts. Use care when handling the plastic parts.

Apply pressure only at the points designated in the maintenance instructions.

Cables and Connectors

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CAUTION: When servicing the notebook, ensure that cables are placed in their proper locations during the reassembly process.

Improper cable placement can damage the notebook.

Cables must be handled with extreme care to avoid damage.

Apply only the tension required to unseat or seat the cables during removal and insertion. Handle cables by the connector whenever possible. In all cases, avoid bending, twisting, or tearing cables. Ensure that cables are routed in such a way that they cannot be caught or snagged by parts being removed or replaced. Handle flex cables with extreme care; these cables tear easily.

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Removal and Replacement Preliminaries

4.3 Preventing Damage to

Removable Drives

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Removable drives are fragile components that must be handled with care. To prevent damage to the notebook, damage to a removable drive, or loss of information, observe the following precautions:

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Before removing or inserting a hard drive, shut down the notebook. If you are unsure whether the notebook is off or in hibernation, turn the notebook on, and then shut it down through the operating system.

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Before removing a diskette drive or optical drive, ensure that a diskette or disc is not in the drive and ensure that the optical drive tray is closed.

Before handling a drive, ensure that you are discharged of static electricity. While handling a drive, avoid touching the connector.

Handle drives on surfaces covered with at least one inch of shock-proof foam.

Avoid dropping drives from any height onto any surface.

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After removing a hard drive, an optical drive, or a diskette drive, place it in a static-proof bag.

Avoid exposing a hard drive to products that have magnetic fields, such as monitors or speakers.

Avoid exposing a drive to temperature extremes or liquids.

If a drive must be mailed, place the drive in a bubble pack mailer or other suitable form of protective packaging and label the package “FRAGILE: Handle With Care.”

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Removal and Replacement Preliminaries

4.4 Preventing Electrostatic Damage

Many electronic components are sensitive to electrostatic discharge (ESD). Circuitry design and structure determine the degree of sensitivity. 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.

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 may not be affected at all and can work perfectly throughout a normal cycle. Or the device may function normally for a while, then degrade in the internal layers, reducing its life expectancy.

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Removal and Replacement Preliminaries

4.5 Packaging and Transporting

Precautions

Use the following grounding precautions when packaging and transporting equipment:

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To avoid hand contact, transport products in static-safe containers, such as tubes, bags, or boxes.

Protect all electrostatic-sensitive parts and assemblies with conductive or approved containers or packaging.

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Keep electrostatic-sensitive parts in their containers until the parts arrive at static-free workstations.

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Place items on a grounded surface before removing items from their containers.

Always be properly grounded when touching a sensitive component or assembly.

Store reusable electrostatic-sensitive parts from assemblies in protective packaging or nonconductive foam.

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Use transporters and conveyors made of antistatic belts and roller bushings. Ensure that mechanized equipment used for moving materials is wired to ground and that proper materials are selected to avoid static charging. When grounding is not possible, use an ionizer to dissipate electric charges.

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Removal and Replacement Preliminaries

4.6 Workstation Precautions

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Use the following grounding precautions at workstations:

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Cover the workstation with approved static-shielding material

(refer to Table 4-2, “Static-Shielding Materials”

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Use a wrist strap connected to a properly grounded work surface and use properly grounded tools and equipment.

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Use conductive field service tools such as cutters, drivers, and vacuums.

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When fixtures must directly contact dissipative surfaces, use fixtures made only of static-safe materials.

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Keep the work area free of nonconductive materials such as ordinary plastic assembly aids and Styrofoam.

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Handle electrostatic-sensitive components, parts, and assemblies by the case or PCM laminate. Handle these items only at static-free workstations.

Avoid contact with pins, leads, or circuitry.

Turn off power and input signals before inserting or removing connectors or test equipment.

4.7 Grounding Equipment and

Methods

Grounding equipment must include either a wrist strap or a foot strap at a grounded workstation.

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When seated, wear a wrist strap connected to a grounded system. Wrist straps are flexible straps with a minimum of one megohm ±10% resistance in the ground cords. To provide proper ground, wear a strap snugly against the skin at all times.

On grounded mats with banana-plug connectors, use alligator clips to connect a wrist strap.

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Removal and Replacement Preliminaries

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When standing, use foot straps and a grounded floor mat.

Foot straps (heel, toe, or boot straps) can be used at standing workstations and are compatible with most types of shoes or boots. On conductive floors or dissipative floor mats, use foot straps on both feet with a minimum of one megohm resistance between the operator and ground. To be effective, the conductive strips must be worn in contact with the skin.

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Other grounding equipment recommended for use in preventing electrostatic damage includes:

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Antistatic tape

Antistatic smocks, aprons, and sleeve protectors

Conductive bins and other assembly or soldering aids

Nonconductive foam

Conductive tabletop workstations with ground cords of one megohm resistance

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Static-dissipative tables or floor mats with hard ties to the ground

Field service kits

Static awareness labels

Material-handling packages

Nonconductive plastic bags, tubes, or boxes

Metal tote boxes

Electrostatic voltage levels and protective materials

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Removal and Replacement Preliminaries

Table 4-1 shows how humidity affects the electrostatic voltage levels generated by different activities.

Table 4-1

Typical Electrostatic Voltage Levels

Event

Walking across carpet

Walking across vinyl floor

Motions of bench worker

Removing DIPS from plastic tube

Removing DIPS from vinyl tray

Removing DIPS from Styrofoam

Removing bubble pack from PCB

10%

35,000 V

12,000 V

Relative Humidity

40%

15,000 V

5,000 V

55%

7,500 V

3,000 V

6,000 V

2,000 V

11,500 V

14,500 V

26,500 V

800 V

700 V

4,000 V

5,000 V

20,000 V

Packing PCBs in foam-lined box 21,000 V

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A product can be degraded by as little as 700 V.

11,000 V

400 V

400 V

2,000 V

3,500 V

7,000 V

5,000 V

Table 4-2 lists the shielding protection provided by antistatic bags and floor mats.

Table 4-2

Material

Antistatic plastic

Carbon-loaded plastic

Metallized laminate

Static-Shielding Materials

Use Voltage Protection Level

Bags

Floor mats

Floor mats

1,500 V

7,500 V

5,000 V

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