Parts and Functions of the Motherboard

Complete Parts of Motherboard

Just study this if you want to pass the exam: The computer Motherboard or shortly MOBO is one of the most important parts of the Personal computer (PC). It is the hardware of the computer installed inside the system unit(CPU).This MOBO hardware act as the mainboard or the central or core assembly of the computer system unit. In other words inside of the CPU case, there are a lot of other hardware's connected to the MOBO, namely: Hard Disk Drive(HDD), CD/DVD ROM, USB Card reader, FDD Drive, processor, RAM, LAN card, Wireless LAN Card, USB expansion board, VGA Card, and the Power Supply Unit(PSU). These are all types of hardware inside the system unit of the Personal Computer.

Computer motherboards designed to take advantage of the most demanding application of a program. One of the most applications is to meet the system requirements of the 3G application. Just like movie games as high innovative applications of computer programming.As the form factor of the motherboard as a series of versions of the MOBO from AT, ATX, BTX, LPX, and NLPX.Compatible words being broadcast, that's why it is the MOBO will synchronize the speed of the processor, RAM, and Video Card(VGA). Unlike only if the MOBO is built-in through the Input/Output ports.

So, let's talk about the Motherboard parts and function to enable you to familiarize the parts and function. This is the most practical approach of the technician. (See the picture above).


1. I/O ports- this is located in the rear panel of the CPU, this use to connect the outside hardware or peripherals of the computer.
  • PS/2 ports- these are used to connect the mouse(green color)and the keyboard(purple color)
  • DB 25 female connector(printer port)-this is used to connect the impact printer, one of that the DOT MATRIX printer, ex. the Epson LX 300 +
  • DB 9 male connector(Serial or com1 port)-this use to connect a serial device of the computer, such as the serial mouse and external modem.
  • VGA port(built-in)- this is used to interface the DB cord of the monitor screen or to connect the monitor screen of the computer. The fastest video card versions are base on the standard of the VGA slots, ex: the AGP and PCIe card.
  • USB 2.0 × 2 ports- these are the ports of the USB devices of the computer. Attached externally of the system unit, one of that is the USB flash drive. As of now the versions or speed of the USB are 1.0 and 2.0 compatible.
  •  LAN port- this called a Local Area Network of the computer. This is used to connect the numbers of nodes or workstations(PC)to form a local area network of the computer within their area. Using a type of communication media such as the network switch and router.
  • Audio Port- this is used to connect the speaker, mic, and MIDI(Musical Instrument Digital Interface) device of the computer
2. ATX Power connector(4 pins)- this is used to connect the 4 pins of the power supply unit(PSU). This is separate from the 20 or 24 pins of ATX power supply to provide DC voltage of the computer processor.
3.  The processor’s ZIF Socket- part of MOBO use to hold the processor or CPU chip(Zero Insertion Force). The compatibility of the socket depends on the computer processor type. Such as the AM2 socket of the AMD and the socket 775 of the Intel company.
4. Memory slot(DIMM)- this is called a Dual Inline Memory Module, this is the slot of computer memory or what we called RAM.The memory slot depends on the type of memory. Such as the PC 133 SDRAM and PC 400 SDRAM-DDR 1.
5. ATX Power connector(24 or 28 pins)- a group of the connector of the MOBO, This is separate of the 4 pin power assignments. It provides a DC power output to the system board(SB)from the output of the Power Supply Unit.
6. Name of the Vendor- this is the manufacturer's name. This is important to know the manufacturer or vendor. So you can download through the internet site the driver's software of the MOBO.
7. CMOS/BIOS BATTERY- In this part, the CMOS/BIOS battery holds, so that it can provide 3 volts direct current/voltage to the CMOS IC to preserve the BIOS settings of the computer. Such as the time module, hardware information, and settings/parameter, etc.
  • CMOS-Complimentary Metal Oxide Semiconductor
  • BIOS- Basic Input/Output System. Is a set of a program stored in CMOS IC, use to preserved the BIOS configuration of the computer
  • CMOS BATTERY PART NUMBER- lithium dry cell CR 2032 3 volts
8. IDE connector(Integrated Drive Electronics)- this connector is used to connect the IDE cable of the HDD(Hard Disk Drive) or CD/DVD ROM to the MotherBoard IDE.
9. Front panel connectors(F-Panel)- this is used to connect the Power LED, HDD LED, Power Switch, and Reset switch of the computer system unit(CPU).
10. SATA connector-this is a Serial Advanced Technology Attachment. The new standard of the IDE connection array of the computer HDD(SATA HDD)to the motherboard system.
11. CMOS/BIOS jumper- this is used to disable the BIOS default setup.Such as to disabled the supervisor password of the BIOS.


  • Turn off CPU
  • change jumper to clear
  • remove the CMOS battery
  • reinsert the BIOS battery
  • change jumper to normal
  • power up computer
  • press “del” or “F2” to enter BIOS setup
12. USB connector(header)- this is used to connect the USB port of the front panel USB 2.0 x 2 port.
13. FDD connector- the connector of the FDD cable through the system board. Normally there are 34 pins out of it to connect the 3.5” 1.44MB Floppy Disk Drive.
14. PCI slots- a part of the computer motherboard use to connect the I/O cards of the computer.Such as LAN card, WIFI card, USB expansion card, and sound card.
15. Motherboard Version number- here you can get the version of the motherboard driver software. So that you can download it exactly to the manufacturer's website.
16. CMOS/BIOS IC- this is the type of BIOS IC being used by the computer MOBO. A set of a program being installed in this IC to preserved the BIOS configuration settings of the computer.Such as the speed of the CPU chip and RAM, etc.
17. AMR slot- this is the AUDIO Modem Riser. Being used to demodulate and modulate the analog audio of the computer.
18. PCI express slot- a part of the computer that holds the computer video card(VGA), the PCIe card.The latest and the fastest card being installed and most compatible with 3d and 4g gaming of the computer. The old video card type is the AGP or Accelerated Graphic Ports and the standard of the PCIe.
19. North Bridge IC- is a passion name as being north of the PCI buses or the PCI slots of the MOBO. The true name of the northbridge is MCI or Memory Controller Hub. Assigned to manage and control the computer memory before the processing of the CPU chip.
20. SouthBridge IC-is a passion name as being south of the PCI buses or PCI slots. The true name of the southbridge is I/O Controller HUB(ICH). It is a type of microchip task to control all the Input and output devices of the computer. Such as the keyboard and mouse. And the monitor screen of the computer, that commonly found at the rear back of the CPU or system unit. 

The computer motherboard is the mainboard, all the connections of the computer connected to these components. As you're computer technicians you need to memorize all the parts needed here. This is very important when you taking up your TESDA exams or whenever you need parts for the replacement of electronic parts of your customer's motherboard.

See you in the next post.
Parts and Functions of the Motherboard combinebasic 5 of 5
Just study this if you want to pass the exam: The computer Motherboard or shortly MOBO is one of the most important parts of the Per...
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About combinebasic

I'm a husband, a blogger and Biomedical Machines Specialist, also a computer instructor and technician and a crazy writer, I like to write and build blogs and avid fan of social media. I have built this blog just to help others through information. Follow us on Facebook and Twitter.

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  1. Yes Annie, this is practical approach how the technician understand through physical inspection of the devices of the computer base of the knowledge and experience.And this is also use to answer the oral questioning of the NC2 exam of the TESDA here in the Philippines.Thanks for visiting my blog Annie nice meeting you here...

  2. thank for giving a wonderful info. hope it help me for my subject

  3. your welcome...just always follow my post

  4. Nice :)
    acronyms please :)

    1. Anonymous all the parts are given and the use and function including the acronym..Kindly tell me what you need or any question regarding acronyms.

  5. Thanks a lot Arnel for this helps me a lot on my review about the parts of motherboard as I'm preparing for job entrance exam here in the Netherlands.I'm so proud of you Kabayan!Mabuhay ka... God bless.

  6. Thanks for that Jean...I'm happy to help you and other people.Are you graduate of CHS of TESDA?

  7. IT helps a lot i will take an exam of chs nc2 tesda.

  8. I am studying now CHS NC2 also.. The information that u given can help a lot.. On the other hand it is more great if you elaborate more of their uses.. and also kindly add pictures for each part so that it can clearly understand. Thank You

  9. Thanks for your message kenneth.I will try to place a picture someday.I will make also a page that have a picture and the description is below on its parts...Good luck for your exam...

  10. hay slamat nka kita rjudt hrap nmang mghanap chs nc2 exam q na bukas

  11. Ok thanks for visiting my blog GodBless for your exam. Be confident of yourself...


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