Chapter 7

Chapter 7

1. Laptops

   • Internal Components
     • An inverter and backlight are two important display components. The inverter converts DC power to the higher voltage AC power that is required by the backlight. The backlight shines through the screen and illuminates the display. Two common types of backlights are cold cathode fluorescent lamp (CCFL) and LED. LED monitors use LED-based backlights that do not have fluorescent tubes or inverters.
       • Wi-Fi antennas transmit and receive data carried out over wireless signals. Wi-Fi antennas in laptops are typically located above the screen, as shown in Figure 1. The Wi-Fi antenna is connected to a wireless card by an antenna wire and antenna leads, as shown in Figure 2. The wires are fastened to the display unit by wire guides, as shown in Figure 3, which are located on the sides of the screen.
   • Expansion Options
     • One of the disadvantages of laptops in comparison to desktops is that their compact design might limit the availability of some functions. To address this problem, many laptops contain PC Card or ExpressCard slots to add functionality, such as more memory, a modem, or a network connection.
       • Cards follow the PCMCIA standard. They come in three types: Type I, Type II, and Type III. Each type is different in size and can attach to different devices. The PC Card slot uses an open standard interface to connect to peripheral devices using the CardBus standard. The ExpressCard is the newer model of expansion card and is the most commonly used. Figure 1 shows a comparison of PC Cards and PC ExpressCards. The PC ExpressCard comes in two models: ExpressCard/34 and ExpressCard/54. The models are 34 mm and 54 mm in width, respectively. Figure 2 shows an example of a PC Card and PC ExpressCard.
         • Here are some examples of functionality that can be added when using PC Cards and ExpressCards: Wi-Fi connectivity Ethernet access USB and FireWire ports External hard drive access Additional memory card reader
           • External Flash Drive An external flash drive, also known as a thumb drive, is a removable storage device that connects to a USB port. An external flash drive, as shown in Figure 1, uses the same type of nonvolatile memory chips as a solid state drive (SSD). As a result, flash drives provide fast access to data, high reliability, and reduced power usage. External flash drives expand the amount of storage space on a laptop and can connect to USB ports. These drives are accessed by the operating system in the same way that other types of drives are accessed.
             • Flash Cards and Flash Card Readers A flash card is a data storage device that uses flash memory to store information. Flash cards are small, portable, and require no power to maintain data. They are commonly used in laptops, mobile devices, and digital cameras. A large variety of flash card models are available, and each varies in size and shape. Most modern laptops feature a flash card reader for Secure Digital (SD) and Secure Digital High Capacity (SDHC) flash cards, as shown in Figure 2. A flash card reader on a standard laptop is shown in Figure 3.
   • Power Settings
     • Advances in power management and battery technology are increasing the time that a laptop can be disconnected from AC power. Current batteries can last up to 10 hours or more without recharging. Configuring laptop power settings to better manage power usage is important to ensure that the battery is used efficiently.
       • Power management controls the flow of electricity to the components of a computer. There are two methods of power management: Advanced Power Management (APM) Advanced Configuration and Power Interface (ACPI) APM is an earlier version of power management. With APM, the BIOS controls the settings for power management. ACPI has replaced APM. ACPI standards, as shown in the figure, create a bridge between the hardware and OS and allow technicians to create power management schemes to get the best performance from a laptop. The ACPI standards are applicable to most computers, but they are particularly important when managing power in laptops.
         • Technicians frequently are required to configure power settings by changing the settings in the BIOS setup. The figure shows an example of power settings in the BIOS setup. Configuring the power settings in BIOS setup affects the following: System states Battery and AC modes Thermal management CPU PCI bus power management Wake on LAN (WOL)
           • The Power Options utility in Windows allows you to reduce the power consumption of specific devices or the entire system. You can manage power usage for the following: Laptop Hard drive Display Sleep timers Low-battery warnings
   • Laptop Components
     • Laptop and desktop computers use the same types of ports so that peripherals can be interchangeable. These ports are specifically designed for connecting peripherals. The placement of ports, connections, and drives is unique because of the compact design of a laptop. Ports, connections, and drives are located on the exterior of the laptop, in the front, back, and side panels. Some laptops contain PC Card or ExpressCard slots to add functionality, such as removable memory cards, a modem, or a network connection. Laptops require a port for external power.
       • Laptops are designed to be compact and portable, while maintaining much of the functionality provided by desktop systems. As a result, essential input devices are built-in to laptops. When a laptop is open, the following input devices may be present:
         • Touchpad Pointing stick Keyboard Fingerprint readers Microphone Web camera
     • Motherboards Desktop motherboards have standard form factors. The standard size and shape allow motherboards from different manufacturers to be interchangeable. In comparison, laptop motherboards vary by manufacturer and are proprietary. When you repair a laptop, it is recommended that you obtain a replacement system board from the laptop manufacturer. Figure 1 shows a comparison between a desktop motherboard and a laptop motherboard. Laptop system boards and desktop motherboards are designed differently. Components designed for a laptop generally cannot be used in a desktop. Laptop and desktop designs are compared
       • RAM Laptops have space restrictions. Therefore, they use Small Outline Dual In-line Memory Modules (SODIMMs)
         • CPUs Laptop processors are designed to use less power and create less heat than desktop processors. As a result, laptop processors do not require cooling devices that are as large as those found in desktops. Laptop processors also use CPU throttling to modify the clock speed as needed to reduce power consumption and heat. This results in a slight decrease in performance, but it increases the lifespan of some components. These specially designed processors allow laptops to operate for a longer period of time when using a battery power source.
     • The purpose of the Function (Fn) key is to activate a second function on a dual-purpose key. The feature that is accessed by pressing the Fn key in combination with another key is printed on the key in a smaller font or different color. Several functions can be accessed:
       • Display settings Display brightness Keyboard backlight brightness Volume setting Sleep states Wireless functionality Bluetooth functionality Battery status
   • Replacing Hardware Devices
     • hese are some signs that the battery, as shown in Figure 1, may need to be replaced: The laptop shuts off immediately when AC power is removed. The battery is leaking. The battery overheats. The battery does not hold a charge.
       • If you experience problems that you suspect are battery related, exchange the battery with a known, good battery that is compatible with the laptop. If a replacement battery cannot be located, take the battery to an authorized repair center for testing. A replacement battery must meet or exceed the specifications of the laptop manufacturer. New batteries must use the same form factor as the original battery. Voltages, power ratings, and AC adapters must also meet manufacturer specifications.
   • Features and OS Configuration
     • Infrared (IR) wireless technology is a low-power, short-range wireless technology. IR transmits data using LEDs and receives data using photodiodes. IR wireless networks are globally unregulated. However, the Infrared Data Association (IrDA) defines the specifications for IR wireless communication. Figure 1 lists common IR characteristics.
       • Three common types of IR networks: Line of sight - The signal is transmitted only if there is a clear, unobstructed view between devices. Scatter - The signal is bounced off ceilings and walls. Reflective - The signal is sent to an optical transceiver and is redirected to the receiving device.
         • Setting up and configuring IR devices is simple. Many IR devices connect to the USB port on a laptop or desktop computer. When the computer detects the new device, Windows 7 installs the appropriate drivers. The installation is similar to setting up a LAN connection.
           • R is a practical, short-range connection solution, but it has some limitations: IR light cannot penetrate ceilings or walls. IR signals are susceptible to interference and dilution by strong light sources, such as fluorescent lighting. Scatter IR devices can connect without the line of sight, but data transfer rates are lower and distances are shorter. IR distances should be 3 feet (1 m) or less when used for computer communications.