CHAPTER 4 MOTHERBOARDS

Introduction :
	The motherboard connects the CPU, hard drives, memory, and every other part of a system by means of slots, connectors, and sockets. The motherboard chipset is a series of chips that is a part of the motherboard. The chipset is very important to the operation of the system.
4.1 Types of Motherboards
	Motherboards differ according the type of system you use. The capacity and efficiency of motherboards differ based on the system type. You can classify motherboards on the basis of system type as desktop motherboards, server motherboards and laptop motherboards.
	4.1.1 Desktop Motherboards
	The desktop motherboard is used in personal computers and desktops. As it is used for applications at home and in office, this type of motherboard is the most basic type.
	4.1.2 Server Motherboards
	Server motherboards are more advanced than desktop motherboards and are designed to offer highend services. These motherboards support expansion and future upgrades and can handle major applications. Server motherboards also offer improved graphics and can usually support different types of memory technology.
	4.1.3 Laptop Motherboards
	A laptop motherboard connects to all the different parts of a laptop system. It is the most important part of the laptop. These motherboards generally have very advanced features as compared to the desktop motherboards.
4.2 Form Factors of Motherboard
	The form factor of a motherboard refers to its physical shape, layout, and the positioning of the components on it. The form factor of the motherboard determines the type of system case it will fit into. Some motherboards that have the same functionality can be packaged in different form factors. The only major difference between such motherboards will be the form factor. Motherboards are available in different forms.
	4.2.1 Advanced Technology (AT) Form Factor
	The AT form factor is also known as the full-size AT form factor. This form factor matches the original IBM AT motherboard in structure and layout. This type of motherboard is very large and is about 12 inches wide and 13.8 inches deep. The AT form factor is not used much by present-day motherboard manufacturers. This type of motherboard does not fit into most of the popular system cases and its size also makes installation and troubleshooting difficult.
	4.2.2 Baby AT Form Factor
	The baby AT form factor was the most popular till recently. This form factor is very much similar to the original IBM XT motherboard structure. The baby AT form factor fits into most of the system cases. A baby AT motherboard is 8.5 inches wide and about 13 inches long. The length of baby AT motherboards is not fixed.
	4.2.3 Low Profile Extended (LPX) Form Factor
	The LPX and mini LPX form factors are used for small Slimline or Low Profile cases. This form factor was developed by Western Digital, who no longer manufactures these motherboards. However, many manufacturers have duplicated the LPX form factor. The LPX form factor has advantages like low cost and small size. However, it is difficult to upgrade or expand. These motherboards also exhibit cooling problems.
	4.2.4 Advanced Technology Extended (ATX) Form Factor
	Intel invented the ATX form factor in the year 1995. The ATX and mini ATX form factors are the most popular ones presently. The ATX form factor has many of the best features of the LPX and AT form factors. The ATX form factor is not compatible with the LPX or AT form factors. As a result, new system cases and power supplies were designed to match this form factor. These cases and power supplies have now become quite common. The ATX form factor makes it easier to install and upgrade motherboards.
	4.2.5 New Low Profile Extended (NLX) Form Factor
	The NLX form factor is a new addition to the motherboard form factors. It was developed by Intel and is similar to the LPX form factor. The NLX form factor was designed keeping in mind easier assembly and reduced cost. These motherboards are designed keeping in mind space efficiency and flexibility.
	4.2.6 Micro ATX Form Factor
	The micro ATX motherboards are small motherboards that are 9.6” in length as well as in width. Lowend PC users generally use this form factor. It has limited expandability and capacity. However, it is quite popular due to its small size and affordability.
4.3 Components of a Motherboard
	The motherboard has several connectors, jumpers and expansion slots for connecting various components of the system. You can connect various devices of the system to the connectors and expansion slots of the motherboard. You can configure the motherboard using the jumpers.
	4.3.1 Connectors
	Network Cables connect the PC to the Internet or any other network. There are different types of network cables. The network cables commonly used are Shielded Twisted Pair (STP), Unshielded Twisted Pair (UTP), Coaxial cable, and Fiber Optic cable.
	_ System panel connector (1) - Accommodates different front panel system functions such as system power LED, hard disk LED.
	_ USB headers (2) -Function as connectors for USB module that can provide two additional USB ports, if the USB ports are inadequate.
	_ Digital audio connector (3) - Connects to a module that provides digital sound output, instead of analog.
	_ MDC connector (4) -Connects to a modem card module
	_ Internal audio connectors (5) - Enable connection to CD-ROM or voice modem card.
	_ GAME/MIDI connector (6) - Connects to a GAME/MIDI module that can connect to MIDI devices.
	_ System Management Bus (SMBus) connector (7) - Used to connect SMBus devices.
	_ ATX 12V connector (8) - Connects to the ATX 12V power supply. The power supply plug will fit these connectors only in one orientation.
	_ ATX Power Connector (9) - Connects to the ATX power supply
	_ CPU and chassis fan connectors (10) - Connect to the system cooling fans.
	_ Serial Advanced Technology Attachment (SATA) connectors (11) - Connect to the SATA hard disk drives.
	_ IDE connectors (12) - Connect to the IDE devices.
	_ Serial port connector (13) - Accommodates a second serial port. This connector uses an optional serial port bracket.
	_ Floppy disk drive connector (14) - Connects to the floppy drive through the floppy drive ribbon cable.
	4.3.2 Expansion Slots
	The expansion slots on a motherboard enable you to connect the expansion cards to the motherboard. The different PCI cards include LAN card, SCSI card and USB card. The cards must comply with PCI specifications. The motherboard has an Accelerated Graphics Port (AGP) slot. You can connect AGP cards that are compatible with your motherboard, to the AGP slot.
	4.3.3 Jumpers
	Jumpers on the motherboard are small pins that enable you to configure settings. A jumper consists of a pair of pins and a small shunt. The shunt can be placed over the pins to short them. The jumper performs different functions when it is shorted and when it is left open, without the shunt. Jumpers vary on all motherboards. They perform different functions, have different settings and are positioned differently in every motherboard. Hence, the motherboard manual is a necessity when you deal with jumpers. The above motherboard has two jumper settings. The Clear RTC RAM allows you to clear the Real Time Clock RAM in the CMOS. By using this jumper, you can clear the CMOS memory of date, time and system setup parameters. You must not use this jumper unless you want to clear RTC RAM. Removing the cap on this jumper will lead to system boot failure. The other jumpers on this motherboard are the USB device wake-up jumpers. You can change the settings on these jumpers to wake the computer from different sleep modes using the connected USB devices. The motherboard also has a CMOS battery that provides back-up power to the CMOS.
	4.3.4 Onboard Components
	The motherboard has several components that are part of the onboard components. These components are sockets, ports and jacks that are integral parts of the motherboard. The other ports, sockets and onboard components of the motherboard are:
	_ CPU socket (1) – Provides the place for the CPU on the motherboard. This socket is a Zero Insertion Force (ZIF) socket.
	_ Northbridge (2) – Forms one of the most important components on the motherboard. It is a chip that handles the communication between the CPU, main memory, AGP Port and another very important component known as the south bridge controller
	_ Southbridge (3) – Handles all the operations of devices and buses that are not controlled by the north bridge.
	_ DDR DIMM sockets (4) – Provide support for the memory using DDR DIMMs. This motherboard has four DDR DIMM sockets.
	_ Super I/O controller (5) – Provides the super I/O functionality.
	_ Flash ROM (6) – Contains the programmable BIOS.
	_ Standby Power LED (7) – Indicates if there is standby power on the motherboard.
	_ Audio CODEC (8) – Enables audio playback by providing DAC channels.
	_ LAN controller (9) – Supports networking functions.
	_ Mouse port (10) – Connects to the PS/2 mouse.
	_ Parallel port (11) – Connects parallel devices like printers.
	_ RJ-45 port (12) – Enables connection to LAN through a hub.
	_ Line In jack (13) – Connects audio devices like a tape player.
	_ Line Out jack (14) – Connects a speaker or a headphone.
	_ Microphone jack (15) – Connects a microphone.
	_ USB ports (16) – Enable connection to USB devices.
	_ Video port (17) – Used to connect to a VGA monitor or another VGA compatible device.
	_ Serial port (18) – Connects the mouse or other serial devices.
	_ Keyboard port (19) – Connects the PS/2 keyboard.
4.4 Bus Architecture
	The buses on a system are the paths through which data is transferred between devices and components on the system. The buses are like the nervous system of the motherboard. These buses are wires located on the motherboard that enable transmission of data. All the components on the system receive and send data through buses. The buses on a system can be classified into two main categories: _ System bus – Connects the CPU, RAM and the optional buffer memory (cache) _ I/O buses – Connects the CPU with other devices such as the peripheral devices The I/O buses are derived from the system bus. The system bus is located on the CPU. The other I/O buses branch out from the system bus. The system bus matches a particular type of CPU. In new systems, the system bus is also called the front side bus. Bus width refers to the amount of data that a bus can carry or transfer at a given instant. Bus width is measured in bits. Bus speed is the speed at which data can move across the bus. Bus speed is measured in megahertz (MHz).
4.5 Bus Standards
	There are different types of I/O buses that transfer data across components of the system. The different buses have different widths and speeds. The common bus standards are: _ Video Electronics Standards Association (VESA) Local Bus – Was the first local bus used in PCs. It is a 32-bit bus that runs at a speed of 33 MHz. VLB was introduced to address video problems in personal computers. VLB is no longer used and has been largely replaced by the PCI bus. VLB slots are used to connect VLB video cards. _ Peripheral Component Interconnect (PCI) Local Bus – Is the most popular I/O bus. It has the same speed and width as the VESA local bus. Some PCI buses have a width of 64 bits. It provides much better performance as compared to the VESA local bus. It has separate circuitry that controls it. PCI generally supports 3 or 4 slots. You can connect video cards, SCSI host adapters and network cards to the PCI expansion slot. _ Accelerated Graphics Port (AGP) Bus – Provides high performance graphics capabilities to a system. This bus forms a dedicated path between the chipset and the graphics subsystem. The AGP bus enables creation of 3D graphics. _ Industrial Standard Architecture (ISA) Bus – Is a widely used standard even though it has remained unchanged since its creation. The ISA bus can support a wide range of devices. It has a bus width of 8 or 16 bits. _ Extended Industrial Standard Architecture (EISA) Bus – Compatible with ISA cards and with a bus width of 32 bits. This standard is rarely found on desktop systems. _ Microchannel Architecture (MCA) Bus – Incompatible with older cards and has a bus speed of 16 or 32 bits. IBM created this standard in the 1980s. This standard is not used nowadays.
4.6 Chipsets
	The term chipset means a set of chips, as the name suggests. It is a group of integrated circuits and microprocessors. The chipset on a motherboard determines its functionality. You must choose your chipset according to the attributes you want your system to have. The chipset and controllers on a motherboard are the intelligence of the system. The chipset therefore affects every aspect of the performance of a system. The chipset controls the data transfers between every component of the system. Previously, a single chip or multiple chips performed every function of the chipset. Over time, all these chips were integrated to form the chipset that controlled system operations. A modern chipset consists of northbridge and southbridge. These two microchips to a large extent determine the features and capabilities of a motherboard. The northbridge handles data communication between the memory and the CPU. Whereas the southbridge handles data from the PCI, ISA slots and other devices that arenot under the control of the northbridge. The type of CPU you use determines the chipset you can use. Every chipset supports a CPU interface. The CPU interface can be Socket 7, Slot 1, or Socket 370. So the chipset that you choose must support the interface required by your CPU. Some of the leading manufacturers of chipsets are Intel, AMD, and VIA. You must choose the appropriate chipset depending on your needs.
	4.6.1 Intel Chipsets
	Intel is the leading manufacturer of chipsets worldwide. You can choose from a wide range of Intel chipsets for your system. Some of the Intel Chipsets with their characteristics are listed below. Chipset Processor Max. Memory USB Ports Type Intel 820E Pentium III, 1 GB 4 Mainstream PC Pentium II Intel 815P Celeron, 512 MB. 2 Mainstream PC Pentium III Intel 915G Pentium IV 4 GB 8 Mainstream PC Express Intel 925X Pentium IV, 4 GB 8 Performance PC Express Pentium IV Extreme
	4.6.2 AMD Chipsets
	AMD manufactures a wide variety of chipsets that are very popular. Listed below are some of the AMD chipsets with their features. Chipset Processor Max. Memory Memory Module USB Ports Size AMD 750 Socket A 768 MB 128 MB 4 Duron/Athlon AMD 760 Socket A 2 GB non-reg., 512 MB 4 Duron/Athlon 4 GB reg. AMD 760 MP Athlon MP 4 GB 512 MB 4 AMD 760 Athlon MP 4 GB 512 MB 4 MPX
	4.6.3 VIA Chipsets
	VIA is another leading manufacturer of chipsets. Some of the IVA chipsets and their features are listed below. Chipset Processor Max. Memory Memory Module USB Ports Size VIA KM133 Socket A 1.5 GB 256 MB 4 Duron/Athlon VIA KLE133 Socket A 2 GB 256 MB 4 Duron/Athlon VIA KM266 Socket A 3 GB SDRAM, 512 MB 6 Duron/Athlon 4 GB reg.
4.7 Configuring a Motherboard
	The motherboard must be configured before it is installed in the system. Motherboard configurationis done with the help of jumpers, which are in red, black or white plastic caps. You must set the clock frequency, PCU voltage and other settings with the help of the jumpers.
	Best Practice
	1. Study the motherboard manual thoroughly for instructions on configuration. The jumper settings vary in every motherboard. 2. Do not take the motherboard or the components out of the antistatic bag unless you are about to begin configuration. 3. Thoroughly inspect the motherboard for any signs of damage to the connectors, jumpers or connectors on the board.
	Precautions
	1. Before touching the motherboard or the components, ground yourself and remove any static electricity in your body. You can do this by touching a safely grounded object or a metal object such as the power supply case. Static electricity can cause damage to the components of the motherboard and CPU. You can also use a grounded wristband for this purpose. 2. Never touch the inside of any component where the ICs are placed. Always hold the components and the motherboard by their edges. 3. Be very careful about the jumper settings. Any incorrect jumper settings on the motherboard will cause permanent damage and data loss. 4. Some motherboard manufacturers set the jumper settings on the motherboard as required by the CPU and other hardware. Other manufacturers do not set the jumper settings as default. You must always cross-check the jumper settings to avoid serious problems later on. 5. Take care not to confuse the labels on jumpers and connectors. Some motherboards have jumpers labeled as JP and connectors as J. If you are not careful, you may interchange the connectors and jumpers. Some motherboards even have connectors and jumpers both labeled as JP. 6. Perform the jumper settings as per the actual bus speed and multiplier settings. Refer to the manual for these parameters of the motherboard.
	Hands on exercise
	To configure the motherboard : 1. Try to physically locate all of the jumpers on the motherboard by looking at the motherboard picture provided in the manual. 2. Set the jumpers for CPU voltage. New processors have two voltage specifications for the CPU and for the external voltages. 3. Set the jumper settings for system bus speed and the multiplier. Some CPUs use a multiplier that is interpreted differently by the CPU. 4. Some systems have a Flash BIOS jumper setting for enabling the Flash BIOS feature. Set this jumper to disabled. 5. Some systems have a CMOS Clear jumper for clearing the contents of the CMOS memory. This feature is required to clear the memory in case of a forgotten password. Ensure that this jumper setting is default, or you will not be able to make any BIOS settings. 6. A Battery Source jumper is available in some systems that decide whether the CMOS memory will be powered by the onboard battery or an external battery. Unless you are using an external battery, ensure that this setting is default (onboard battery). 7. Some motherboards have Disable jumpers that allow you to enable or disable motherboard parts. Ensure that these jumpers are set properly. However, it is best not to disable any parts of the motherboard. 8. After configuring the motherboard, re-check all the settings again. System problems caused by incorrect motherboard configuration can be very serious and difficult to diagnose.
4.8 Installing a Motherboard
	Motherboard installation is a complicated task. You must read and understand the motherboard manual thoroughly before you attempt to install or configure the motherboard. You must be very careful while performing motherboard installation, as any incorrect step can cause permanent damage. Before installing the motherboard, you must install the CPU, fan and heat sink on the motherboard. After installing the CPU, fan, memory and heat sink on the motherboard, it appears ready for installation .
	Best Practice
	1. Turn off the system and remove the power cord from the socket. 2. If you uninstall any component, never place it on the ground. You must always place it on an antistatic pad or in the bag that was provided with the component. 3. Do not connect power to the system if you suspect any damaged parts on the motherboard.
	Precautions
	1. Ensure that the motherboard power supply is switched off or that the power cord is detached from the power supply before you add or remove any components on the motherboard. If the motherboard power supply is switched on during installation, it will cause severe damage to the motherboard components.
	Hands on exercise
	To install the motherboard : 1. Remove the system case. 2. If the drive tray is removable, remove it out of the system case. This will make the process of motherboard installation easier. Removing the Drive Tray 3. Install the ATX plate in the system case. While doing this, ensure that the mouse and keyboard connectors are towards the power supply. Align the plate in place by pressing from the inside, Aligning the ATX Plate 4. Compare the drive tray to the motherboard layout. There must be a standoff installed on the drive tray at every location on the motherboard that has a mounting hole. These locations must match on the drive tray and the motherboard. Comparing the Motherboard to the Drive Tray 5. Install the standoffs on the drive tray in the appropriate location. The standoffs that come with the motherboard may be of different varieties and must be positioned carefully, so that they are not interchanged. Installing the Standoffs 6. Place the motherboard on the drive tray after fixing the standoffs. All the standoffs must be visible through the holes in the motherboard. Placing the Motherboard on Drive Tray 7. Attach the motherboard to the drive tray by fixing the different screws. Start with the centermost screw and work outwards in a star pattern. You must not tighten the screws too much, as this will damage or crack the motherboard. Fixing the Motherboard to Drive Tray 8. From the system case, find the different connectors such as the hard drive LED, speaker, and reset connectors. Follow the instructions on the manual to connect these parts to the connectors on the motherboard. Connecting to the Motherboard 9. Fix the power connector from the power supply to the motherboard. Fixing the Power Supply 10. Fix the drive tray back into the system case. Ensure that the motherboard does not touch the system case or the drive tray directly. Touch the motherboard gently to ensure that it is rigid and tightly fixed. The motherboard should not bend when touched. Fixing drive Tray to System Case 11. Most of the present-day motherboards are provided with additional connector brackets for connecting USB ports, game ports and IEEE 1394 ports. To properly connect the additional connector brackets, you must remove an adapter slot cover. Removing Adapter Slot Cover 12. Fix the connector bracket onto the PCI slot. Fixing Connector Bracket 13. Connect the different port connectors to the appropriate connectors or slots on the motherboard. Follow the instructions in the manual. Connecting the Port Connectors 14. To complete the system installation, you must connect the additional adapter cards and drives to the motherboard. After the system installation is complete, you must verify whether all the connectors and jumpers are properly installed. If any of these components do not work, refer to the motherboard manual and correct the connections.
4.9 Troubleshooting Motherboards
	If your system crashes repeatedly, it is possibly due to the motherboard failure. However, actual motherboard failure is very rare. It is possible that some other problems like a loose connection, power failure or overheating is causing system failure.
	Best Practice
	1. Turn off the system and remove the power cord. 2. Check the connections on the motherboard. 3. If you have made any changes to the BIOS settings, restore them to the default value. 4. Ensure that the motherboard is not touching the system case or the drive tray. 5. Check whether there are any cross connections between wires.
	Precautions
	1. Wear an anti static wristband. 2. Do not place any removed components on any place other than an antistatic package.
4.9.1 Instability in a New System
	A newly assembled system may show problems like frequent error messages and problems in starting up. These problems can be caused by a variety of reasons like loose connections or incorrect settings. Some of the problems can also be caused by the motherboard.
	1. Check all connections and cables on the motherboard. The connections must be tight and must be placed properly. 2. Ensure that the motherboard with the CPU, video card, and the memory is properly connected to the power supply. 3. Check the system temperature and ensure that the heat sink and fan are working properly. 4. Check whether the power supply is burdened with more devices and components than it can handle. If you have upgraded your system or added a device, the power supply must be able to handle it. 5. The system memory may have failed. Check the system memory and ensure that is connected and configured properly. Also check whether the memory is compatible with the motherboard. 6. Check the jumper settings on the motherboard. 7. Inspect the CPU for any problems. 8. Check the BIOS settings and ensure that they are correct. Set the BIOS settings as default. 9. Inspect the expansion cards on the motherboard for proper correction and configuration. 10. Ensure that the hard disk drives have proper jumper settings. 11. Check the IRQ settings of the system for any conflicts that can arise during system assembly or addition of new hardware. 12. If your cache is corrupt or incompatible, it may lead to motherboard problems. Disable cache in BIOS. If the system works properly, then the cache was faulty. 13. If the system does not work properly, check whether the cache is properly installed.
4.9.2 Motherboard has a Crack
	If the motherboard is not properly handled, it may develop cracks. This can also happen if you connect components on the motherboard with too much force. This is a very rare problem and may require replacement of the motherboard.
	1. If your motherboard is new, the crack may have been caused due to poor handling during delivery. In this case, contact the manufacturer and get the motherboard exchanged. 2. If the motherboard is an old one, inspect the mounting of the motherboard on the system case. If the motherboard bends under pressure, add plastic supports to support it. 3. If the motherboard works, you can ignore the problem, as it is irreparable. If the motherboard does not work, you must buy a new one.
4.9.3 System does not Work Properly after Recent Repair
	If the system is moved, opened or repaired, there is a chance of cables getting disconnected or shorted. Loose memory modules can also be a cause of such a problem.
	1. Open the system case and check it for any loose components or cables. Loose cables or screws can cause serious problems like shorts in the system. 2. Check whether any cables are too tight or wound up. Cables that are too tight can be accidentally broken. Check the connectors of cables and try to rearrange the connections to loosen cables that are too tight and wound up or twisted. 3. Ensure that there are no cross connections or physical interference between components and cables. 4. Check whether the motherboard bends under pressure. If it does, install additional plastic supports. 5. Ensure that the motherboard does not touch any part of the system case. 6. Screws that connect the motherboard must not touch any wire. Any screw that has a chance of touching a wire accidentally must have an insulating washer inserted under it. 7. Ensure that no standoff on the drive tray is touching the underside of the motherboard. 8. Check the connections between the LEDs and switches on the motherboard as well as the system case. 9. Ensure that the power supply is properly connected to the motherboard. 10. If there any unused power connectors, make sure that they are not touching any part of the system. 11. Check the connections to the drives and the fan of the system. 12. Examine the CPU. It must be properly inserted in the slot on the motherboard. You can remove the CPU and reinsert it. 13. The fan of the PCU must be attached to it properly. 14. Examine the memory SIMMs and DIMMs. They must be securely in place. 15. Ensure that all the expansion slots are in place and are not interfering with any part of the motherboard.
4.9.3 System does not Work Properly after Recent Repair
	If the system is moved, opened or repaired, there is a chance of cables getting disconnected or shorted. Loose memory modules can also be a cause of such a problem.
	1. Open the system case and check it for any loose components or cables. Loose cables or screws can cause serious problems like shorts in the system. 2. Check whether any cables are too tight or wound up. Cables that are too tight can be accidentally broken. Check the connectors of cables and try to rearrange the connections to loosen cables that are too tight and wound up or twisted. 3. Ensure that there are no cross connections or physical interference between components and cables. 4. Check whether the motherboard bends under pressure. If it does, install additional plastic supports. 5. Ensure that the motherboard does not touch any part of the system case. 6. Screws that connect the motherboard must not touch any wire. Any screw that has a chance of touching a wire accidentally must have an insulating washer inserted under it. 7. Ensure that no standoff on the drive tray is touching the underside of the motherboard. 8. Check the connections between the LEDs and switches on the motherboard as well as the system case. 9. Ensure that the power supply is properly connected to the motherboard. 10. If there any unused power connectors, make sure that they are not touching any part of the system. 11. Check the connections to the drives and the fan of the system. 12. Examine the CPU. It must be properly inserted in the slot on the motherboard. You can remove the CPU and reinsert it. 13. The fan of the PCU must be attached to it properly. 14. Examine the memory SIMMs and DIMMs. They must be securely in place. 15. Ensure that all the expansion slots are in place and are not interfering with any part of the motherboard.
4.9.4 System does not start up though Fans are working
	In some cases, you may not be able to access the drives and the video also may not work. If the system does not start up, but the system fans work fine, it is mostly either a motherboard or CPU problem.
	1. Remove the CPU and reseat it on the motherboard. 2. Check the seating of the CPU on the motherboard and ensure that it is locked down. 3. Ensure that the motherboard power supply is properly connected. 4. Check all the ribbon cables to see that they are connected to the appropriate drives and are oriented properly. 5. Reset the BIOS settings to default. 6. Try the safe booting procedure with power up defaults, by referring to the motherboard manual. 7. If the system does not start up, the memory, CPU or motherboard are faulty. 8. Remove any additional memory and try starting with the minimum memory. Then swap the memory and try starting the system. If the system starts with either of the memories, then the other memory is faulty. 9. Check all jumpers and connections on the motherboard. 10. Check the motherboard expansion slots for metal fragments. 11. Replace the CPU on the motherboard. If the system works, the CPU is faulty. 12. If the system doesn't work with the new CPU, try placing the CPU on another motherboard. If it works, then your motherboard is faulty.