12.2.4 Practice Questions

You have a mobile device that provides a touchscreen, but does not have touchscreen technology embedded into the display. Which of the following mobile device display components provides the touchscreen functionality?

> Digitizer Explanation: If a touchscreen is not embedded into the display during manufacturing, a thin glass digitizer is placed in front of the display to read touch events. An inverter converts DC power to AC power for the screen. OLED and LCD are types of mobile device displays. They do not provide touchscreen technology.

Which of the following LCD display technologies is the BEST choice for use on touchscreen displays?

> In-plane switching (IPS) Explanation: In-plane switching (IPS) has a high response rate. This is your best choice for touchscreen displays. Twisted nematic (TN) was used in early LCD displays to enable a display with batteries. This technology is not used with touchscreen displays. Vertical alignment (VA) was an early adoption of color LCD. While it produces a truer black and offers a wider viewing angle, it suffers from distortion when transitioning colors and is not used for touchscreen displays. A touch screen digitizer (TSD) is not an LCD display technology. It is used if a touchscreen is not embedded into the display during manufacturing. A TSD is a thin glass digitizer that is placed in front of the display to read touch events.

Which of the following mobile device display components provides the required power for a mobile device's screen?

> Inverter Explanation: LCD monitors are backlit. In order to produce a bright enough light, an inverter is included on the laptop's motherboard (or may be part of the display). The inverter converts DC power to AC power for the screen. If a touchscreen is not embedded into a mobile device display during manufacturing, a thin glass digitizer is placed in front of the display to read touch events. The digitizer does not provide any power to a mobile device screen. Both TN (twisted nematic) and IPS (in-plane switching) are types of LCD technologies. They do not provide any power to a mobile device screen.

You have recently purchased a new, foldable smart phone. Which of the following types of mobile device display technologies is MOST likely being used for the foldable display?

> OLED Explanation: OLED is taking over, and many devices that use LCD are transitioning to OLED. OLED is thinner and lighter than LCD and can be made flexible, allowing for the development of foldable smartphones. TN (twisted nematic), VA (vertical alignment), and IPS (in-plane switching) are all types of LCD technologies. They do not allow flexible folding of a mobile device display.

You have ordered and are about to replace an LCD screen on a laptop device. You have already placed the laptop on a static mat, attached a static wristband, and unplugged the laptop. What is your next step in replacing the LCD screen?

> Remove the battery. Explanation: After you place the laptop on a static mat, attach the static wristband to your wrist, and unplug the laptop, you should then remove the battery. After removing the battery, you can then remove the bezel, the screen, and the video ribbon.

Your older notebook LCD display often goes dim or sometimes blank. Which of the following would be the BEST first step to resolve this issue?

> Replace the CCFL inverter. Explanation: If the display on your older notebook often dims or goes blank, it is probably an indication that your LCD screen is using a CCFL inverter to backlight the LCD display. The CCFL inverter needs to be replaced. Replacing the inverter is much less expensive than replacing the LCD display. The video ribbon is probably not the cause of a dimming screen. The bezel is the frame around the LCD display. The bezel does not hold the actual screen in place. Tightening down the bezel screws would have no impact on a dimming screen.

Which of the following are advantages of using an OEM replacement LCD display? (Select two.)

> The LCD display is guaranteed to work as a replacement. > The LCD display is the same quality as the screen you are replacing. Explanation: When purchasing an OEM part, you are guaranteed that the part will work as a replacement. You also will have confidence that the part is of the same quality as the part you are replacing. OEM parts are generally a lot more expensive than aftermarket (non-OEM) parts. Some aftermarket parts can actually be better quality than OEM parts and much cheaper as well. Aftermarket (non-OEM) parts are not specific to any particular notebook manufacturer and are instead created specifically as generic replacement parts.

You have recently been given an older laptop to use for performing basic tasks such as sending emails and editing documents. However, when the display changes from one color to another, you notice that there is some distortion in the image. Which of the following LCD technology types is MOST likely being used for the LCD display?

> Vertical alignment (VA) Explanation: Vertical alignment (VA) produces a truer black and offers a wider viewing angle. However, this type of LCD display often suffers from distortion when transitioning colors. Twisted nematic (TN) was used in early LCD displays. TN displays used low operating voltages, making their use with batteries possible. They are still used for monochrome alphanumeric displays and do not distort images. IPS (in-plane switching) has a high response rate and is used in LCD displays, as this technology does not distort images when changing colors. IPS is the best choice for use on touchscreen displays. Organic light-emitting diode (OLED) is a display technology that is gradually replacing LCD. OLED is not an LCD technology.

Which of the following mobile device components are often installed under the bezel of a mobile device display? (Select three.)

> Webcam > Microphone > Wi-Fi antenna wires Explanation: Manufacturers often use the display bezel to run wires for the Wi-Fi antenna or to integrate a webcam or microphone. The touchscreen digitizer is placed in front of the mobile device display to read touchscreen events. An inverter converts DC power to AC power for the screen. The inverter may be included in the device's motherboard or be part of the display. OLED is a type of display, not a component that is installed under the bezel. OEM stands for original equipment manufacturer and is often referred to when deciding on whether or not to purchase replacement parts for a mobile device display.

You are removing the bezel from a laptop's LCD display screen. After several attempts to pry up the bezel and remove it, you have not separated the bezel from the case. Which of the following is the MOST likely reason for your inability to remove the bezel?

> You missed a screw. Explanation: If you reach a point where the bezel will not separate, you have probably missed a screw. Bezels are attached with screws and are designed to be removed for internal replacement purposes. If the bezel is glued in place, it means that it has been tampered with. While using a metal tool to pry up the bezel can scratch or damage it, you can still do so if you feel it is important enough.