Motherboards 1

The Motherboard or System Board is the spine of the computer. Purpose: It is the component that connects all of the other components of a PC together. Every piece of hardware, directly or indirectly plugs into the motherboard. All data and commands flow from one place to another by using buses known as traces, which are embedded in the motherboard. 2

Motherboards Modern motherboards are officially printed circuit boards (PCBs) and come in multiple layers. You can see some of the traces on the boards, but every motherboard is two or more layers thick. The fact that a motherboard is multi layered, makes it possible to have smaller motherboards, and thicker thus stronger. When the motherboard is small, the distances are shorter, therefore data flow is faster. 3

Motherboards All motherboards are defined by 3 interrelated characteristics: 1. Components 2. Form Factors 3. Chipset A good technician should be able to make a recommendation to a client when choosing a motherboard, according to the above 3 characteristics. 4

Motherboards Form Factor: determines the layout and dimensions of a motherboard, and the locations of components and ports. Chipset: defines the type of CPU and RAM required for the motherboard, and determines the built-in devices supported by the motherboard, including the expansion slots. Built-In Components: determine the core functionality of the system 5

Components CPU Socket RAM Slots Chipset Northbridge Southbridge Super I/O ROM CMOS Battery Video Card Slot AGP PCI-e Expansion Slots PCI Cards Power Connectors IDE Connectors SATA Connectors Peripheral Connectors 6

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Form Factors The Form Factor determines the layout and dimensions of a motherboard. All of the motherboards come in a basic rectangular shape, but vary in the size and the layout of built-in components. Mainly, a form factor relates to the case and the power supply of a PC. The case must be designed in a way to fit the motherboard, and the power supply and the motherboard need matching connectors. 11

Form Factors Motherboards come in standard form factors. We will focus on the following form factors: – AT & Baby AT – LPX & NLX – ATX – BTX … and variants of these Most PC cases are only designed to work with one form factor. 12

Form Factors - AT AT – Advanced Technology The old style motherboards follow a form factor called AT, also known as Full AT. At is now obsolete. The AT form factor invented by IBM in the early 1980s. It was the predominant form factor through the mid 1990s. The processor, memory and expansion slots are all in line with each other. 13

Form Factors - AT At had a relative large keyboard port. The problem with AT was the lack of external ports. In fact, at that time, the only devices plugged into an average PC were a monitor and a keyboard. Over the years, AT had to be replaced because the number of devices plugged into the back of the PC has grown. AT motherboards catered for just a monitor and a keyboard. An average PC today includes keyboard and mouse, printer, speakers, monitor and USB devices. 14

Form Factors - AT As technology improved and the PC flourished(تطورت), the demand for smaller PCs increased. Manufacturers created a smaller motherboard by placing the same components in a smaller area - Baby AT. The problem with the Baby AT was the placing of the components, which resulted in limited expandability and overheating 15

Form Factors - AT 16

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Form Factors – LPX & NLX Added components created demand for a new standard form factor. One form factor that enjoyed a degree of success was the slimline factor. The first was known as the LPX (Low Profile Extended). It was then replaced by the NLX. In this type of form factor, you have a small riser in the center with cards attaching to it horizontally. The aim is to use the space optimally. 18

Form Factors - LPX 19

Form Factors - NLX 20

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Form Factors - ATX ATX – Advanced Technology Extended There continued to be a tremendous demand for a new form factor – a form factor that had more standard connectors, but at the same time was flexible enough for possible changes in technology. This led to the creation of the ATX form factor in ATX got to a slow start but by around 1998, ATX took over AT to become the most common form factor used today. 22

Form Factors - ATX The ATX form factor includes many improvements over AT. The position of the power supply enables better air movement. The CPU and RAM are placed to enable easier access. Other improvements, such as the placement of the RAM closer to the Northbridge and CPU, than on AT boards, which results in better performance. New smaller ports for the motherboard and keyboard were introduced, known as PS/2. 23

Form Factors - ATX ATX motherboards use a feature called soft power. This means they can use soft power to turn the PC on and off. Instead of the thick power cord used in AT systems, an ATX power switch is a pair of small wires leading to the motherboard. Later version of ATX are the microATX and the FlexATX, the latter being the smallest ATX motherboard. 24

Form Factors - ATX 25

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Form Factors - BTX BTX – Balanced Technology eXtended. Even though ATX took care of ventilation(تهوية), heat remained a problem because of faster CPUs and powerful graphics cards. Therefore BTX was introduced. So the aim of BTX is to create the coolest new form factor today, and any change in the design was done specifically to improve cooling, by managing heat by one single air flow! 27

Form Factors - BTX These are the main changes in the design of the BTX: – The I/O Ports and the expansion slots have changed sides on the actual board. – CPU moved to the front of the motherboard to get cool air from the front of the case. – A new fan & heatsink system was introduced, known as the ‘thermal unit’. – Finally, the thermal unit blows the air directly outside the case, and not in the case itself, like the fan in the ATX. BTX comes in 3 versions: BTX, micro BTX and picoBTX. 28

Form Factors - BTX 29

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Form Factors – ATX vs BTX 31

Chipset Every motherboard has a chipset. The chipset defines the motherboard in many ways, determining which processor type and memory type it can use, and what sort of internal and external devices the motherboard will support. Chipsets vary in feature, performance and stability, so they factor hugely in the purchase or recommendation of a particular motherboard. 32

Typical Chipset Diagram 33

Chipset Because the chipset facilitates communications between the CPU and other devices in the system. The chipset component chips are relatively centrally located on the motherboard. Most modern chipsets are composed of two primary chips: - Northbridge chip - Southbridge chip 34

Chipset – Northbridge & Southbridge The Northbridge chip is responsible for AGP communications and memory communications. Since Northbridge chips deal with memory, they do a lot and thus get pretty hot, so they get their own heat sinks. The Southbridge chip is responsible for onboard peripherals such as audio, storage drives, network and expansion buses. Most Southbridge chips do not include a heatsink. So the Northbridge is responsible for high-speed motherboard components, while the Southbridge is responsible for lower speed components. 35

Chipset – Super I/O Old technologies such as ISA slots, floppy drives, infrared, parallel ports, serial ports and PS/2 were supported by the Southbridge. Modern chipsets hardly support these devices anymore, so manufacturers created a third chip – Super I/O to handle such devices. 36

Chipset including Super I/O Northbridge, Southbridge, &Super I/O 37

Chipset Every device on the PC needs BIOS support so that the CPU knows how to use that device properly. The chipset is no exception. The System ROM chip provides part of the BIOS for the chipset. The chipset still needs support for the rest of the things it can do. This is done by using Software Drivers. You have to load the proper drivers for the specific OS. 38

Chipset - Manufacturers Both INTEL and AMD make chipsets. They lead the market, though they have some serious competition, like VIA Technologies and NVIDIA Corporation. Chipset manufacturers do not always use the terminology of Northbridge and Southbridge. They create their own chip names. For example, while AMD use the terms Northbridge and Southbridge, INTEL uses the terms Memory Controller Hub and I/O Controller Hub, respectively. 39

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Serial ATA (SATA) is an IDE standard for connecting devices like optical drives and hard drives to the motherboard. SATA cables are long, thin, 7-pin cables. One end plugs into a port on the motherboard, usually labeled SATA, and the other into the back of a storage device like a hard drive SATA Connector 48

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Choosing the Motherboard and Case Choosing a Motherboard and case can prove quite a challenge for a technician: 1. First, determine what motherboard you need. 2. Second, make sure the form factor of the motherboard matches with the case. 3. Third, use the motherboard manual to find out what features does the motherboard provide and configuration details 4. Fourth, select the case that matches space needs and the motherboard’s form factor. 55

Choosing the Motherboard and Case 1. First, determine what motherboard you need. Are the motherboard and CPU compatible with each other? Possibly, when you buy a motherboard and a CPU, choose a motherboards that works with higher speeds than the CPU, so that you can upgrade later without changing the motherboard. Figure out how much RAM is supported by the motherboard, and the number of memory slots in the motherboard. 56

Choosing the Motherboard and Case 2. Second, make sure the form factor of the motherboard matches with the case. Form factors determine the size and layout of the motherboard, so different form factors fit within different cases. Don’t try to put a regular ATX motherboard intro a microATX case! 57

Choosing the Motherboard and Case 3. Third, use the motherboard manual to find out what features does the motherboard provide and configuration details All motherboards come with a technical manual. The manual contains all of the critical information about the motherboard. One typical instance when we need the manual, is when we need to find out certain CMOS settings and how to deal with them. 58

Choosing the Motherboard and Case 4. Fourth, select the case that matches space needs and the motherboard’s form factor. Cases come in 6 basic sizes: slimline, desktop, mini-tower, mid-tower, tower, and cube. Cases come with or without the following features: Removable face Detachable motherboard mount Front-mounted ports and power supply 59

Troubleshooting Motherboards Motherboards fail, not often but both motherboards and their components can die form many causes: time, dust or simply slight manufacturing defects. Installing cards, electrostatic discharge, flexing the motherboard one time too many when swapping RAM or drives – any of these factors can cause a motherboard to fail. 60

Troubleshooting Motherboards Motherboard failures commonly fall into three types: o Catastrophic Failure – The PC won’t boot. o Component Failure – Intermittent problems mostly o Ethereal Failure – PC reboots itself & blue screens 61

Troubleshooting Motherboards Catastrophic Failure The PC just won’t boot. Happens with brand new systems (burn-in failure) due to manufacturing defect and systems that get a shock of ESD. Burn-In-Failure usually happens within the first 30 days due to a motherboard problem. 62

Troubleshooting Motherboards Component Failure Intermittent problems Happens because of bad connections between a device and the motherboard. The problem here is actually in the motherboard itself. Usually if you replace the device, you will still have the same problem. 63

Troubleshooting Motherboards Ethereal Failure PC reboots itself & Blue Screens Staff doesn’t work all the time. The causes are usually the following: o Faulty Component o Buggy Device Driver o Buggy Application Software o Slight Corruption of the Operating System o Power Supply Problems 64