Laptop Hardware & Components | CompTIA A+ 220-1001 | 1.1

In this video you will learn about the installation and configuration of laptop hardware and its components.

Hardware/Device Replacement

Before we get started, due to the size of a laptop in comparison to that of a desktop computer, a laptop has an integrated display, keyboard and network hardware.  Laptops also use specialized or proprietary components for hard drives, optical drives, system boards, memory, CPUs, and other components.  Replacing these devices involves much different procedures than on a desktop computer.

Some general differences include:

  • Component Sources:  Replacement components such as display, keyboard, wireless network card, and system board are available only from the original equipment manufacturer (OEM).  These are known as OEM parts.  Other components, such as optical drives and hard drives, memory, and the CPU can be purchased from third-party sources but differ greatly from their desktop counterparts.
  • Power Sources:  A laptop is powered by an internal battery and an AC adapter that also charges the battery.  As with other laptop components, the original vendor is the most typical source for replacements, although some third-party vendors may sell “universal” replacement AC adapters that work.
  • Components Unique to Laptops:  Laptops include several components typically not included on desktop computers, including an antenna in the display that is connected to a mini-PCIe card to provide wireless networking, a keyboard with an integrated touchpad or pointing stick, a touchscreen or non-touchscreen display, and integrated speakers.

These differences, along with the extensive use of plastics and the use of tiny screws, make servicing a laptop a major challenge, even for those who are experienced with servicing a desktop computer.

Laptop Access

Here are several best practices you should use when you need to disassemble a laptop to get access to its internal hardware to either upgrade or replace defective components:

  • Refer to Manufacturer Documentation:  Documentation helps you properly identify screw types, screw lengths, number of screws (some laptops have more than 100), cable and component locations, and other information needed.  Most vendors offer this information online, but some manufacturers insist on doing repairs themselves and do not provide documentation for access to these computers.
  • Use Appropriate Hand Tools for Case Disassembly & Component Removal:  Using recommended tool types and sizes helps prevent problems such as damaging screw heads by using a screwdriver that is too large.  Repair documentation typically lists the recommended tools for each procedure.  Proceed with caution.  If you break a part of the laptop, you won’t be able to buy it locally but will usually have to order a replacement.
  • Document & Label Cable and Screw Locations:  Laptops typically use a mixture of screw lengths and sometimes screw types.  Mix them up, and you could damage components or end up being unable to secure them properly.  Taking photos at different stages of disassembly may help in the reassembly process.
  • Organize Parts:  Consider using a multiple-compartment parts tray with a lid for parts sorting and storage.  A magnetic dish also helps prevent loss of parts.
Magnetic Dish Storage

If you need to replace the battery, mass storage (hard disk, SSD, SSHD, or optical drive), SODIMM RAM, or wireless adapter on a typical laptop, you need to access these components from the bottom of the laptop.  Understand, some laptops use a single cover for all upgradeable components rather than multiple covers.  Some laptops require disassembly to access the hard disk drive or SSD mass storage.  Check your system documentation for details.

FIG 1.1 & 1.2


If a laptop keyboard or its pointing device (touchpad or pointing stick) fails, you must replace the unit.  A laptop with a touchpad has a keyboard that is separate from the touchpad, whereas a laptop with a pointing stick has a pointing stick that is integrated with the keyboard.  Some laptops have both types of pointing devices.

Laptop Touchpad
Laptop Pointing Stick

Hard Drive Storage (HDD)

Most laptop computers use one 2.5 inch storage drive that comes in one of three common choices:  HDD, SSD, or SSHD.  Each has strengths and weaknesses, and each could be the right choice, depending on the scenario presented:

  • Hard Disk Drive (HDD):  These magnetic disks have been a standard option for years and combine low cost with large capacity.  However, they are slower than the other options.  With magnetic disks and moving parts that can wear down, they are the least reliable of the three options.
Laptop HDD
  • Solid-State Drive (SSD):  SSD is a flash memory drive with no moving parts.  It is much faster than an HDD when booting and storing or retrieving data.  Although SSDs currently cost more money than HDDs, their prices are dropping and their capacity is improving.  Many newer laptops have M.2 expansion ports and can support an M.2 SSD card that is directly mounted to the circuit board for even faster reading.
Laptop SSD
  • Solid-State Hybrid Drive (SSHD):  An SSHD combines a solid-state cache with magnetic capacity.  It uses a memory manager to choose the most common files for the fast cache.
Laptop SSHD
Comparison of HDD, SSD, & SSHD

Note:  Some Ultrabooks use the 1.8 inch or 2.5 inch SSD form factor (HDD or SSD).  The larger 3.5 inch drive form factor is used in desktop drive enclosures or in desktop computers.


RAM Review

Things to keep in mind before you can select the right memory upgrade for a laptop:

  • Form Factor:  Most laptops in service use DDR2, DDR3, or DDR4 SODIMMs.
  • Memory Speed:  If you plan to add a module, make sure it is the same speed as the existing module.  If you plan to replace the modules, buy a matched set of modules in the fastest speed supported by the system.
  • Memory Timing:  The most common way to refer to memory timing is by its column address strobe (CAS) value.  If you install memory modules that use different CAS values, the laptop could become unstable and crash or lock up.

How to determine the correct memory to use for a memory upgrade:

  • Use the interactive memory upgrade tools available from major third-party memory vendors’ websites:  These tools list the memory modules suitable for particular laptops, and some use an ActiveX web control to detect the currently installed memory.  Crucial System Scanner is a very useful tool for showing what’s currently installed and what is compatible.
  • Check the vendor’s memory specifications:  You can determine part numbers by using this method, but this method is best if memory must be purchased from the laptop vendor rather than from a memory vendor.

Generally, laptops have two connectors for memory, typically using small outline DIMMs (SODIMMs), which are reduced-size versions of DIMM modules.

SODIMM Features

Smart Card Reader

A smart card reader is a data input device that reads data from a card-shaped storage medium.  Smart card readers are typically used on corporate laptops for access control (do not confuse it with a flash memory card reader).  Smart cards are usually plastic with an embedded chip to authorize a user for access.  They are not a common option for home use.

External Smart Card Reader

Optical Drives

Although not as common in most modern laptops these days, some laptops feature modular USB optical drives designed for being swapped.

Laptop Optical Drive
Laptop USB External Optical Drive

Mini PCIe

A peripheral component interconnect (PCI) slot in a computer is a slot for plugging in add-on peripherals.  This slot provides access to the motherboard for a device such as a WiFi modem, a video graphics processing unit (GPU), or added storage with an M.2 card.  miniPCI Express (mPCIe) cards perform functions similar to those of the PCIe card, but they are designed for the compact space of a laptop.  The mPCIe slots in a laptop are used for plugging in wireless cards and also for M.2 memory modules.  Other examples of modules that can plug into mPCIe slots are GPS units, cellular cards, and analog-to-digital converter (ADC) cards.

Mini PCIe (mPCIe) Card

Wireless Card

A laptop with WiFi or Bluetooth support typically uses either an mPCIe expansion card or an M.2 card to provide wireless network support.  The M.2 card form factor (also called NGFF, for next-generation form factor) is also used for SSD and other I/O devices.  Note that an M.2 card slot made for SSD cannot be used for WiFi or Bluetooth cards.  Regardless of which wireless card a laptop uses, there are two antennas that lead from the WiFi antennas built into the display panel that need to be connected to the card.

Laptop WiFi Card
Laptop WiFi Card Antennas

Cellular Card

Some laptop users require connectivity no matter where they are in the field.  Because cellular access is sometimes needed because WiFi is not available, some business-class laptops come with slots for cellular LTE wireless connectivity.  Cell providers offer data-only services for data access but these plans are not set up for calling or messaging.  Cell providers also offer service plans for external USB LTE modems.  To enable cellular on a laptop, it is best to start by consulting the manufacturer’s documentation for the location of the slot for the SIM card.

Laptop Cellular Cards

USB Travel Routers and Wireless WAN Cards

Another option for traveling users is a mobile hotspot.  Each cell provider has its own version of a hotspot and can add a hotspot with a data plan to the user’s cell account.

USB Wireless Internet Card

Video Card

As stated earlier, the mPCIe slot in a laptop may be used for a video graphics processing unit (GPU).  Gaming users often enhance the GPUs on their gaming machines.

Laptop Video GPU

Laptop Screens

A computer display screen typically consists of a liquid crystal display (LCD) or an organic light-emitting diode (OLED) display, and any communication peripherals are added separately.  Laptop screens are specially designed to accommodate a webcam, microphone, WiFi antennas, and often touchscreen digitizers and inverters.  An LCD screen uses a backlight to illuminate light-modulating liquid crystals.  When an electric current passes through the crystals, they arrange into patterns that become the image on the screen.  LCD screens are customized to different device types, and some have WiFi antennas attached.  OLED screens are in many ways advanced compared to LED screens.  They are brighter and use less energy (saving on battery use) and are flexible and foldable.  But the screens themselves are much thinner and more subject to cracking or breaking when dropped or mishandled.

DC Jack

The DC jack (also referred to as the power adapter port) receives DC power from the AC/DC power adapter and passes it to the battery.  If the DC jack fails, the laptop’s battery cannot be charged, and the laptop cannot run on external power either.

Laptop DC Jack
Laptop AC/DC Adapter


A failing laptop battery can be a source of all kinds of problems for the user.  Most manufacturers have diagnostic software that reports on the health of the battery and estimates how many cycles are left.  It is best to be proactive in battery replacement.  If you need to purchase a replacement battery for a laptop, you may consider a larger-capacity battery, if one is available for the model being repaired.

Laptop Battery

Caution:  Take precautions against ESD when you change the battery.  Discharge any static electricity in your body by touching a metal object before you open the battery compartment and don’t touch the contacts on the battery or the contacts in the battery compartment with your hands.


Most laptops use plastic bezels, case covers, and frames (sometimes referred to collectively as plastics/frames).  These can be cracked during normal use or during replacement or upgrades to internal components.


If you have failed speakers, you can check for several possible problems before resorting to replacing them.  Things you should check out before replacing speakers include the obvious, such as volume settings & audio output settings, & the not-so-obvious, such as audio cable connections, audio driver updates, and securing the seating on the sound card.

Laptop Built-In Speakers

System Board

System boards typically come in a variety of shapes which is dependent upon the design of the laptop. Laptop system boards are not easily replaceable.

Laptop System Board


Before replacing the CPU in a laptop, you must determine which models are supported by the installed motherboard.  Laptop motherboards are customized for a narrow range of CPUs.  A UEFI/BIOS update might enable additional CPUs to be used successfully.

Laptop CPU

Cooling Fan

The cooling fan in a laptop might be part of the heat sink or might be attached to the laptop’s enclosure.  If the cooling fan in a laptop fails, many components may be damaged or destroyed.

Laptop Internal Cooling Fan & Heatsink