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Computer Servicing for Beginners

Computer Servicing

The hardware in a computer system is like the engine of a car. The software is like the driver. Just as a car cannot be run without the engine, a computer needs perfectly functioning hardware components to be working properly.

The first time you open a computer case, it can be quite daunting looking at all of the components, wires, etc. As a computer technician, it is essential to be immediately able to identify the components in different computer systems. Not all computers are the same as there are many different layouts and components used.

Different Systems
Be aware that computers come in different configurations and are manufactured by different vendors; therefore the physical appearance of the individual components will be different. Don’t be surprised when you encounter a component which looks a bit different while you are disassembling or assembling it.


The Main Components


This is the component which is used as the fixing board for the rest of the components. Motherboards come with various slots for the various different components to be fixed onto them. The type of motherboard depends on the sort of CPU (central processing unit) it has been designed for. When choosing a motherboard you have to be careful because they are built only for a particular type of CPU and they are not interchangeable.

As everything you have on the PC at some point needs the motherboard, you need to consider these components when buying a motherboard. For example, if you have a lot of devices with a PCI (Peripheral Component Interconnect) interface that you wish to use, there is little point buying a motherboard that only offers three PCI slots. Like wise with memory, you have to make sure that there are enough slots for the amount of memory you have or wish to have.

CPU (Central Processing Unit)

The Central Processing Unit (CPU) is like the brain of the computer. It is the component which does the arithmetic calculations and will help the computer to perform better. It is measured in megahertz (MHz); 1000 megahertz makes a gigahertz (GHz). Each type of CPU fits into a specific socket of the motherboard. There are two main manufacturers of CPUs for PCs - Intel and AMD (Advanced Micro Devices). They each produce a range of CPUs; Intel's most popular ones being Celeron, Pentium, Core and AMD's being Sempron and Athlon. CPUs will be geared to provide functionality at different budget (price) points, and aimed at different types of user (i.e. businesses, gamers etc.).

The CPU is usually covered by a heat sink and a fan. These are extremely important because without them the CPU will become extremely hot. A ZIF (zero insertion force) socket is a chip socket that allows you to insert and remove a chip without special tools.

Internal Data Path

The heart of the CPU is the Arithmetic Logic Unit (ALU). The ALU performs all data processing functionality. To assist the ALU, internal ‘temporary storage’ areas known as CPU registers hold data before and after processing.  The bit size of the information that can be held and processed by the registers and the ALU determines the CPU’s overall performance.

External Data Path

Although a CPU might have, for example, a 16 bit internal data path, its external data path which allows it to communicate with the rest of the PC might not be this wide. Although a smaller external data path will slow the performance of the CPU, it makes it simpler to upgrade earlier system designs to use a new processor.

Cooling System

It is necessary to have a cooling system to remove heat from the computer. There are different types of cooling systems. For example, conventional fan, water based and liquid based. Depending on the amount of heat that is generated from the computer during processing, different types of cooling systems will be required.


There are two types of memories: RAM (random access memory) and ROM (read only memory).  RAM is electromagnetic storage that loses all its data once the computer has been turned off. RAM is used by the operating system and other programs, like an office application or music program etc., in order to store data that is required at speed. Computers with large amount of memory often perform faster simply because the CPU is not idle waiting for data to be retrieved from slower components such as the hard drive and which can be stored in memory.

There are 3 main types of RAM: SDRAM (Synchronous Dynamic RAM) and DDR (Double Data Rate SDRAM) and RAMbus DRAM (DRAM).

DRAM is the most common form of RAM. It’s called dynamic RAM because it can only hold data for a short period of time and must be refreshed periodically. DRAM comes in two major forms: DIMMS and RIMMS. DIMMS are 64-bit components and RIMMS use only 16-bit interface but run at a higher speed than DDR.


An area of RAM reserved for data recently read from disk, which allows the processor to quickly retrieve it if it's needed again.

Clock Speed

Also called clock rate, the speed at which a microprocessor executes instructions. Every computer contains an internal clock that regulates the rate at which instructions are executed and synchronizes all the various computer components. The CPU requires a fixed number of clock ticks (or clock cycles) to execute each instruction. The faster the clock, the more instructions the CPU can execute per second. Clock speeds are expressed in megahertz (MHz) or gigahertz ((GHz).

The internal architecture of a CPU has as much to do with a CPUs’ performance as the clock speed, so two CPUs with the same clock speed will not necessarily perform equally, since it is not always directly proportional to the performance level. If you double the clock speed but leave all other hardware unchanged, you will not necessarily double the processing speed. Therefore, the newer processors would be at least 20 times faster than the older processors even if their clock speeds were the same. In addition, some microprocessors are superscalar, which means that they can execute more than one instruction per clock cycle.

Removable Drives

Removable drives include hard disk drives, solid state drives, flash drives, CD/DVD/Blu Ray drives, Zip Drives (a floppy disk storage system which is still used today). Zip drives (and Floppy Disks) are a superseded technology and not provided in new PCs, however as a repair technician, you may come across them in older machines. Keychain drives/portable USB drives are currently the most common source of removable drive.

Network Cards

Network cards are used for connecting to the local area networks. If there is going to be more than one network card installed on a computer, you have to make sure that the motherboard has enough slots for it.


Modems are both internal and external but external modems are extremely rare these days because all new computers feature internal modems. They are used for internet (and intranet - a private network used by a business) and fax connections,which may be through wireless, cable, cellular, or dial-up connections.

Computers are an integral part of our world - learn more about them

We really so heavily on computers in our daily lives, that being able to understand more about them can be invaluable.

  • If you know more about computers you can not only make sure you choose (or spec.) one more suited to your needs, but you can save yourself time, money and frustration, by having an idea of what to do if it goes wrong.
  • As a career prospect, developing your knowledge of computers can provide a springboard for working as a computer technician and then enabling progression into other areas of the industry.

From introductory courses, such as Computer Servicing I, to Computer Networking and other IT based courses we offer a wide selection of studies to provide you with the knowledge to start out and progress in the IT industry.

If you are thinking of pursuing an IT career, or you just want to improve your own knowledge to help in your business or at home, have a look at our range of courses shown in the links lower down this page.

Our IT tutors are highly knowledgeable and experienced. If you have any questions or want help in determining which study path to choose to meet with your aims, then get in touch with our IT specialists today - they will be pleased to help you.

[27/01/2021 22:02:31]

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