9 Laptop and Mobile Device Hardware Flashcards
Primary differences between laptops and desktops:
Portability
Cost
Performance
Expandability
Quality of Construction
Three overarching characteristics of mobile devices that make working with them unique versus working with laptops or desktops:
field servicing/upgrading
input methods
secondary storage
Field Servicing and Upgrading
To service closed mobile devices of any size, you have to seek out an authorized repair facility and take or send your device to them for service. Attempting your own repairs can void any remaining warranty, and it can possibly render the device unusable. Many of today’s mobile devices, including some of the larger tablet-style devices, have no field-serviceable parts inside, let alone user-serviceable parts. In some extremes, special work environments similar to the original clean manufacturing environment have to be established for servicing.
Touch Screen Input Methods
Nearly all mobile/portable devices are equipped with touch screens, supplying onscreen keyboards and other virtual input interfaces. Many are capable of detecting more than one contact point. This technology is referred to in the industry as multi touch.
Secondary Storage
Data must survive brutal conditions. The most popular solution is to equip mobile devices with very small solid-state drives (SSDs) in place of larger magnetic or solid-state drives. There are no moving parts, the drive stays cooler and resists higher temperature extremes, and SSDs require less power to run.
A typical laptop case is made up of three main parts:
1 The display—usually an LCD or organic light-emitting diode (OLED) display
2 The case structure, which is the metal reinforcement inside the laptop that provides rigidity and strength and to which most components are mounted
3 The case, or the plastic or aluminum cover that surrounds the components and provides protection from the elements
Most cases are typically made of some type of plastic (usually ABS plastic or ABS composite) to provide for reduced weight as well as strength.
Safety steps to take before working on a laptop:
- Turn off the computer.
- Disconnect all external peripherals and cables, such as keyboards, mice, monitors, and network cables.
- Unplug it from the power source.
- Ensure that your workspace is free of clutter and well lit.
- Have the manual or help videos handy, just in case.
- Make sure you have the proper tools readily available. (This might include a phone to take pictures with.)
- Ground yourself with an ESD wrist strap or other antistatic protection.
Video Memory Sharing
If your video card is built into your motherboard, it likely will share system memory with the processor. That will slow
everything down. Shared memory is configured in the system BIOS/UEFI. Each BIOS/UEFI is different. Keep in mind that some BIOSs/UEFIs will allow you to set aside only a certain amount of memory for video memory. After upgrading the memory, you will need to go into the BIOS/UEFI and reconfigure how much memory you want allocated to the video card.
Inverter
A small circuit board behind the LCD panel that takes DC current and inverts it to AC for the backlight. Flickering screens or dimness indicate a bad inverter. Inverters store and convert energy, which means they have the potential to discharge that energy. Make sure any replacement inverter was made to work with the LCD backlight that you have.
Liquid Crystal Display (LCD)
LCDs are based on the electrical property that when a current is passed through a semi-crystalline liquid, the crystals align themselves with the current. Transistors are then combined with these liquid crystals to form patterns, such as numbers or letters. LCDs are lightweight and have low power requirements. Liquid crystals do not produce light, so LCD monitors need a lighting source to display an image
Three popular variants of LCD monitors:
in-plane switching (IPS)
twisted nematic (TN)
vertical alignment (VA)
Twisted Nematic (TN)
Restricted viewing angles and not the best color reproduction. Colors may appear washed out or too blended together. They have very little lag and can handle high refresh rates (popular with gamers and inexpensive).
in-plane switching (IPS)
They have the best viewing angles and color
reproduction of all LCD monitors. They usually have a bit more lag than TN monitors do, but the difference is minimal in higher-end models.
vertical alignment (VA)
VA has the best contrast ratios of the three, meaning the difference between the dark and bright colors is the best. Color reproduction tends to be good but not quite as good as IPS, and VA monitors do have a bit more lag.
Organic Light-Emitting Diode (OLED)
An OLED is the combination of the compound and the electrodes on each side of it. If thin-film electrodes and a flexible compound are used to produce the OLEDs, an OLED display can be made flexible. Because OLEDs create the image in an OLED display and supply the light source, there is no need for a backlight, so power consumption is less than it is in LCD panels. The contrast ratio of OLED displays exceeds that of LCD panels.
Digitizer
A digitizer is a device that can be written or drawn on, and the content will be converted from analog input to digital images on the computer. Digitizers take input from a user’s
finger or a writing utensil, such as a stylus. When built into the display, they might be the glass of the display itself, or they might be implemented as an overlay for the display.
