Hardware Device Replacement
As a computer technician, you might be called on to replace a number of components in a laptop. Some, such as memory, hard disks, and optical drives, require little disassembly; whereas others, such as the keyboard, CPU, and LCD display, might require more extensive disassembly processes.
The following sections provide general guidance. For details, consult the service manual for the particular laptop you need to repair.
Battery Removal and Replacement
Remove the battery and AC power source before performing any other component replacements, as follows:
1.Turn off the computer.
2.Disconnect the AC adapter or line cord from the computer.
3.Open the battery compartment in the unit; it might be secured by a sliding lock or by screws.
4.If the battery is under a removable cover, remove the battery compartment cover.
5.Open the lock that holds the battery in place.
6.Slide out or lift out the battery (see Figure 3-5). If the battery is a flat assembly, it might be held in place by a clip; push the clip to one side to release the battery.
7.Examine the battery contacts inside the computer for dirt or corrosion, and clean dirty con-tacts with a soft cloth.
To replace the battery, follow these steps:
1.Examine the battery contacts inside the computer for dirt or corrosion, and clean dirty con-tacts with a soft cloth.
2.Examine the battery’s own contacts for dirt or corrosion, and clean dirty contacts with a soft cloth.
3.Line up the guides on the side of the battery with the corresponding holes in the battery compartment and swing the battery into place.
4.If the battery is under a removable cover, replace the cover.
5.Reconnect the AC adapter or line cord.
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1. Releasing the battery catch
2. Rotating the battery up and out of the battery compartment
Figure 3-5 Removing a battery from a typical laptop computer.
Keyboard Replacement
Follow these steps to replace the keyboard:
1.Position the laptop so the bottom of the unit is facing upwards.
2.Remove the screws that hold the keyboard in place.
3.Turn over the laptop.
4.Open the screen so the keyboard is visible.
5.If necessary, remove the bezel that holds the keyboard in place.
6.Lift up the keyboard to expose the keyboard cable.
7.Remove any hold-down devices used to hold the keyboard cable in place.
8.Disconnect the keyboard cable from the system board (Figure 3-6).
9.Remove the keyboard.
To install the replacement, reverse these steps.
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Carefully pull keyboard cable loose
Keyboard cable
Figure 3-6 Removing the keyboard cable.
Hard Drive or SSD
Follow this procedure to remove and replace a 2.5-inch hard disk or solid-state disk (SSD) acces-sible from the bottom of the laptop (3.5-inch hard disks are used by desktop computers):
1.After disconnecting power sources, turn over the laptop so that the bottom of the laptop faces upward.
2.Loosen or remove the screw or screws used to hold the drive cover in place.
3.Slide the cover away from the retaining lug or clips and remove it. On some systems, the drive might be mounted to the cover (see Figure 3-7a). On other systems, the drive is mounted to the chassis (see Figure 3-7b).
4.If the drive is fastened to the chassis, as in Figure 3-7b, remove the screws holding the drive to the chassis.
5.Slide the drive away from the retaining screw holes and lift it out of the chassis.
6.Remove the screws fastening the drive to the drive cover or frame (see Figure 3-8).
7.Remove the drive from the drive cover or frame.
8.Insert the new hard disk into the drive cover or frame.
Reverse these steps to install the new hard disk. Older systems use a 44-pin portable version of the PATA interface; newer systems use the SATA interface.
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A
B
Figure 3-7A laptop hard disk that fastens to the cover (a) compared to one that fastens to aseparate frame inside the chassis (b).
A
B
Mounting screws
Figure 3-8 Removing the hard disk mounting screws from the cover (a) or the frame (b).
After the system is restarted, enter the BIOS setup program to verify that the new hard disk has been properly recognized by the system.
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Memory
Because most laptops have only two SODIMM memory sockets, it is often necessary to remove one or both memory modules before upgrading to a larger amount of RAM. Here’s how to remove and replace SODIMMs:
1.After disconnecting all power sources, remove the cover over the memory upgrade socket on the bottom of the system.
2.Remove any screws or hold-down devices.
3.Remove the old SODIMM memory modules if necessary. To remove a memory module, pull back the clips on both sides and swing the memory up and out.
4.Insert the new memory upgrade, making sure the contacts (on the back side or edge of the module) make a firm connection with the connector.
5.Push the top of the module down until the latches lock into place (see Figure 3-9). Repeat Steps 4 and 5 for each module you install.
| Push SODIMM | Push rear of module until |
| module into slot | latches lock into place |
Locking latches
Figure 3-9 Installing an SODIMM module on a typical portable computer.
6.If the memory socket uses screws to secure the memory in place, install them.
7.Close the cover and secure it to complete the upgrade.
Optical Drive
If you need to upgrade to an optical drive with more capabilities or you need to replace a defective optical drive, follow this basic procedure:
1.After disconnecting all power sources, turn the laptop over so that the bottom faces upward.
2.Locate the latch that holds the drive in place, or locate the mounting screw that holds the drive in place and unscrew it. It might be located inside the access panel for another compo-nent, such as the mini-PCI board or memory modules.
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3.Slide open the latch or remove the mounting screw.
4.Slide the drive out of the system. See Figure 3-10 for a typical example.
To reinstall the drive, reverse the preceding steps.
Mini-PCI and memory module compartment
Optical drive being Hole for drive retaining bolt removed from system
Figure 3-10 Removing an optical drive from a typical laptop.
Wireless Card or Mini-PCIe
Most wireless cards use the mini-PCI or newer mini-PCIe form factor shown in Figure 3-11. If the card is damaged or needs to be upgraded, follow this procedure.
To remove a mini-PCI or mini-PCIe card, follow this basic procedure:
1.Verify the location of the card. Some laptops have the card under the keyboard; others have the card located under a removable cover on the bottom of the computer.
2.After disconnecting all power sources, place the computer appropriately for access to the card.
3a. If the card is located under the keyboard, remove the keyboard bezel and remove the key-board.
3b. If the card is located under an access panel, remove the screws holding the access panel in place.
4.Disconnect any wires connected to the adapter. They might be screwed into place or snapped into place. Note their position.
5.Push the card out of the connector and remove it from the system.
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Mini-PCI Mini-PCIe
Figure 3-11A typical mini-PCI Type III modem (left) compared to a typical Mini-PCIe card (right).Image source: Wikimedia Commons.
To reinstall the card or replace it with a different card, reverse these steps.
Screen
The LCD display is the single most expensive component and also one of the easiest to break. Here’s how to remove it:
1.After removing power from the system, if the system has an integrated Wi-Fi (wireless Ethernet adapter), disconnect the antenna leads attached to the adapter (usually a mini-PCIe or mini-PCI card).
2.Remove the keyboard frame and keyboard.
3.Disconnect the FPC cable (display cable) from the system board; this cable transmits power and data to the LCD display assembly (see Figure 3-12).
4.If the system has integrated Wi-Fi, remove the antenna leads from the clips in the top cover.
5.Rotate the display assembly to a 90-degree angle to the base unit.
6.Remove the screws that secure the display assembly.
7.Pull the display assembly free from the base unit.
To replace the display, reverse the preceding steps.
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Fan Wi-Fi antenna leads
Power to display
Figure 3-12Wi-Fi and laptop display power cables must be disconnected during the screenremoval process.
CPU
The CPU cannot be replaced without removing the fan and heat sink module. If the fan is separate from the heat sink, follow this procedure:
1.After removing power from the system (including the battery), remove other components as directed. These might include the hard drive, WLAN cover, optical drive, keyboard, key-board cover, display assembly, and top cover.
2.Depending upon the specific unit, you might need to turn over the system.
3.Remove the screws holding the fan in place.
4.Disconnect the fan’s power lead from the motherboard.
5.Lift the fan out of the system. Retain it for reuse.
Laptop heat sinks are typically one-piece or two-piece units that pull heat away from the chipset as well as the processor. Some units incorporate the fan. To remove the heat sink (see Figure 3-13), follow these steps:
1.Remove the screws holding the heat sink in place.
2.If the heat sink incorporates a fan, disconnect the fan power lead from the motherboard.
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3.Lift up on the heat sink to remove it (move it from side to side if necessary to loosen the thermal material). Retain it for reuse.
4.If some components that use a heat sink are located on the reverse side of the motherboard, turn over the motherboard and repeat steps 1-3. For example, the system shown in Figure 3-13 has a separate heat sink for the graphics chipset (a) and the CPU (b).
(a) (b)
Figure 3-13 Heat sinks for the graphics chipset (a) and CPU (b) on a typical laptop computer.
To remove the CPU, follow these steps:
1.Loosen the processor locking screw. Note the markings on the CPU and the socket. The CPU must be aligned in the same position when installed.
2.Remove the CPU from the socket. Retain it for possible reuse (see Figure 3-14).
(a) (b)
Figure 3-14 A typical laptop processor (a) and its socket (b).
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Remove old thermal material from fan or heat sink parts you are reusing. See the instructions with a new CPU for applying thermal material during installation.
DC Jack
The DC Jack receives DC power from the computer’s AC/DC power converter and routes it to the motherboard. It is typically part of a cable assembly that also contains the cable that carries power to the motherboard.
To replace it, follow these steps:
1.After removing power from the system (including the battery), remove other components as directed. These might include the hard disk, WLAN cover, optical drive, keyboard, key-board cover, display assembly, hinges, and top cover.
2.Unclip the DC jack from the case.
3.Unclip the power cable leading from the DC jack from the case.
4.If the power cable connector is not accessible, remove other components as needed to access it, such as the system board or ExpressCard assembly.
5.If necessary, turn over the system board to access the power connector.
6.Disconnect the power cable connector from the system board.
To install the replacement DC jack, reverse these steps.
System Board
Accessing the system board (motherboard) requires almost complete disassembly of the computer. Follow this basic procedure:
1.After removing power from the system (including the battery), remove other components as directed. These might include the hard drive, WLAN cover, optical drive, keyboard, key-board cover, display assembly, hinges, and top cover.
2.Unclip the DC jack from the case.
3.Unclip the power cable leading from the DC jack from the case.
4.If the power cable connector is not accessible, remove other components as needed to access it, such as the system board or ExpressCard assembly.
5.If necessary, turn over the system board to access the power connector (see Figure 3-15).
6.Disconnect the power cable connector from the system board.
7.Remove the old system board.
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Power cable
CPU
Heat sink
RAM sockets
Figure 3-15The underside of a typical laptop motherboard. (Figure 3-12 shows a portion of thetop of the same motherboard.)
For reassembly, reverse the preceding steps.
Before reassembling the computer, swap any components on the old system board to the new one. These might include the following:
CPU and heat sink (Be sure to remove old thermal material and use new thermal material as needed.)
Fans
RTC (CMOS) battery
ExpressCard or PC Card assembly Mini-PCI or mini-PCIe module
Other components, such as memory, are reinstalled after the system is reassembled.
Touch Pad
If you need to replace the touch pad, you need to partially disassemble the portable computer.
1.Check service documents to determine whether the touch pad is a separate component or if it is built in to the top cover. If the touch pad is built in to the top cover, remove the top cover.
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2.If the touch pad is a separate component, remove components that block access to the screws that hold the touch pad in place. These might include the hard drive, WLAN cover, optical drive, keyboard, keyboard cover, display assembly, and top cover.
3.Place the system so that the bottom of the system faces up.
4.Disconnect the cable from the pointing devices to the motherboard.
5.Remove the clips or screws holding the touch pad in place.
6.Remove the touch pad assembly.
To replace the touch pad, reverse these steps.
Plastics
Most of the outer shell of a laptop consists of several plastic subassemblies. However, a typical plastics kit includes the removable covers over components such as the hard drive and memory, and might include items such as the bezel for the optical drive and the rubberized feet for the bot-tom of the unit.
To replace any of these items, follow these steps:
1.Remove power from the laptop.
2.Turn over the unit.
3.Remove the old component by unscrewing it (covers) or prying it off (bezels or feet).
To replace a component, reverse the previous steps.
Speaker
To remove speakers, follow this basic procedure:
1.After removing power from the laptop, remove components that block access to the speak-ers. These might include the hard drive, WLAN cover, optical drive, keyboard, keyboard cover, display assembly, and top cover.
2.If necessary, turn the laptop over.
3.Disconnect the num lock cable or other cables as directed.
4.Remove the screws holding the speakers in place.
5.Lift out the speakers.
To replace the speakers, reverse these steps.
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Laptop Display Components
One of the most important considerations in choosing a laptop is its display. Use the following sec-tions to review the most important features about laptop displays.