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Hardware Fundamental Week 1-lab 1 Safety Precautions When Servicing a PC • Safety Precautions Safety precautions can be divided into four categories: • The most important precautions • Things to do before you start working on a computer • Things to watch for while you are working on a computer • Things to do once you have finished working on a computer The Most Important Safety Precautions • Know what you are doing ...and if you aren't sure then find out: read the manual, check web sites, ask people. • Make backups If you lose data, you can recover it from your backups. • Turn off the electricity This will prevent electrocution and death. • Do not open computer monitors!!! They can build up large amounts of electricity. Only properly trained technicians taking special precautions can do this. •Before Working On a Computer • • • • • • Make backup copies of your data. Make a copy of your BIOS (CMOS) settings. Shut down the computer properly. Turn off the electricity to your computer at the wall. Leave the power cord plugged in. Make sure that you have a clear work area. Wear an anti-static strap and connect the clip to the computer case. • While You Are Working On a Computer • • • • • Do not open a computer monitor. Handle components carefully. Handle components by the edges; avoid touching any metal contacts. Keep components in their anti-static packaging until you are ready to use them. Watch for any screws or other metal objects that fall into the computer. Watch out for sharp edges inside the computer! Once You Have Finished Working On a Computer • Make sure that no screws or other metal objects have fallen in to the computer. • Make sure that all components that need to be in the computer are there! • Make sure that all components are properly secured. PORTS PORTS DIN (Deutsches Institut für Normung) A variety of keyboard connectors • DIN-5 IBM-PC • PS2 Mini-DIN-6 http://www.nullmodem.com DB-25 connector • “D”-shaped shell, 25 pins •Seemingly everywhere in the computer Industry •Serial / parallel / SCSI connections DE-9 / D-sub 9 pin connector is often mistakenly referred to as a “DB-9” • “D”-shaped shell, 9 pins • Used for a variety of purposes • Serial / Video (IBM) RJ_11 ,RJ-45 •Commonly used for network cabling and for telephony applications •Under special circumstances it can be used for serial applications The Motherboard Motherboard Communication • The largest and most important circuit board: Also known as the main board or system board – Contains the CPU, expansion slots, memory , and other devices • Categories used to group motherboard components – Processing, temporary storage, communication, power Motherboard Communication • All devices communicate with CPU on motherboard • A peripheral device links to motherboard via cable or wireless • Some motherboard ports outside of the case: – Keyboard, mouse, parallel, USB ports, sound ports Form Factors Form factors are industry standardized shapes and layouts that enable motherboards to work with cases and power supplies. Form factor specifies the physical dimensions of major system components. Typical AT Typical ATX ATX Difference Between AT & ATX Motherboards • Size and Orientation • Both AT and ATX motherboards have been produced in various sizes throughout the years. the form factors fit in different computer cases depending on their size. An ATX motherboard is positioned at a 90 degree angle from the positioning of AT motherboards. As a result, you can never use an AT case with an ATX motherboard because it will not fit. • • • • • • Power Use A notable difference between the ATX motherboard and the AT motherboard is the addition of "sleep" mode to the ATX form factor. Sleep mode is a power management mode in which some of the components are powered down to save power, but parts of the computer remain ready to boot. The sleep mode reduces the use of power when the computer is not in use, while still allowing you to more quickly revive the computer and return to where you left off. Difference Between AT & ATX Motherboards • Power Connectors • • • • The power connectors also differ between AT and ATX motherboards. AT motherboards use two 12-pin plugs to power the motherboard. An ATX motherboard uses one 20-pin plug for the power supply. When using an ATX form factor motherboard, you must use an ATX power supply. You can use the pin number to identify whether you have the correct power supply for your motherboard. • • Connectors • The outside connectors on the AT and ATX motherboards are the most visibly noticeable difference between the two form factors. The AT form factor motherboard is limited to one outside connector, a five-pin DIN connector for the keyboard. An ATX-style motherboard is built to incorporate many other connectors, including connections for network cards, video cards, sound cards and modems. • • AT power Connector ATX Power Connector ATX 24 pin Power connector 20pin Atx power ATX Battery Power to CMOS Memory • Types of CMOS batteries • 3.6V lithium battery with a four-pin connector; connects with a Velcro strip • 4.5V alkaline battery with a four-pin connector; connects with a Velcro strip • 3.6V barrel-style battery with a two-pin connector ; soldered on. • 3V lithium coin-cell battery (most common) The coin cell is the most common type of CMOS battery CMOS is short for Complementary Metal-Oxide Semiconductor. CMOS is an on-board semiconductor chip powered by a CMOS battery inside computers that stores information such as the system time and system settings for your computer. The standard lifetime of a CMOS battery is around 10 Years. However, this amount of time can change depending on the use and environment that the computer resides. Single Edge Contact (S.E.C.) Cartridge Slot 1 (also Slot1 or SC242) is a Slot-type connector with 242 contacts This connector was designed for Pentium II family of processors, and later used for Celeron budget line of processors. Pentium III was the last microprocessor family that used the Slot 1. This motherboard supports both Slot 1 and Socket 370 for Pentium III chips. What is S.E.C. Cartridge Packaging? A 242-pin slot on the motherboard that holds Intel CPU modules including the Intel Single Edge Contact Cartridge. The Pentium II was the first to use Slot 1. Pin grid array • A pin grid array, often abbreviated PGA, refers to the arrangement of pins on the integrated circuit packaging. • In a PGA, the pins are arranged in a square array that may or may not cover the bottom of the package. PGAs are often mounted on printed circuit boards via two methods, through hole or by using a socket. PGAs are primarily used in applications that require more pins than what older packages such as the dual in-line package (DIP) provide. Land grid array The land grid array (LGA) is a type of surfacemount packaging used for integrated circuits. It can be electrically connected to a PCB either by the use of a socket or by soldering directly to the PCB. The LGA is used as a physical interface for microprocessors of the Intel Pentium 4 Intel Core 2, Intel Core and AMD families. Unlike the pin grid array(PGA) interface , there are no pins on the chip; in place of the pins are pads of bare gold-plated copper that touch pins on the motherboard. Intel CPU Chart AMD CPU Chart