REVIEWER-CSS.docx

**CSS: 1^ST^ MID LESSONS** **12 OHS PROCEDURES FOR COMPUTER HARDWARE SERVICING NC II** OHS (Occupational Health and Safety) refers to the legislation, policies and activities that aim to protect the health, safety and welfare of all the workplace. **(D A T B A D C H A M C U)** 1. **DO NOT WORK A...

**CSS: 1^ST^ MID LESSONS** **12 OHS PROCEDURES FOR COMPUTER HARDWARE SERVICING NC II** OHS (Occupational Health and Safety) refers to the legislation, policies and activities that aim to protect the health, safety and welfare of all the workplace. **(D A T B A D C H A M C U)** 1. **DO NOT WORK ALONE** so that there's someone who can take care of you in case of emergency. 2. **ALWAYS POWER OFF AND UNPLUG** the computer after working on it. 3. **TAKE AWAY ANY LIQUID** near your working area to prevent electrocuting or accidentally damaging the computer. 4. **BE CAREFUL WITH TOOLS** that may cause short circuit. 5. **ALWAYS GROUND AND DISCHARGE** yourself before touching any parts of the computer. 6. **DO NOT USE EXCESSIVE FORCE** if things don't fit in. 7. **CLEAN THE AREA** before and after using it to maintain sanitation and prevent accidents. 8. **HOLD THE COMPONENTS ON THEIR EDGES** and do not touch the Integrated Circuit (IC) parts. 9. **ALWAYS WEAR PERSONAL PROTECTIVE EQUIPMENT (PPE)** in accordance with the organization's OHS procedures and practices. 10. **MAKE SURE THAT THE PINS ARE PROPERLY ALIGNED** when connecting a cable connector. 11. **CONTINGENCY MEASURES** during workplace accidents, fire, and other emergencies are recognized. 12. **USE BRUSH AND COMPRESSED AIR** or blower in cleaning the computer system. **INTRODUCTION** Basic parts of a desktop computer are the: **computer case (system unit case), monitor, keyboard, mouse, and power cord.** Each of this parts plays an important role whenever you use a computer. **PARTS AND FUCNTION:** - **COMPUTER CASE:** This can be metal or plastic, this holds the main components of the computer. It houses the motherboard, CPU, power supply, RAM, and HDD. - **MONITOR:** The monitor **works with a video card,** which is located inside the case. The monitor displays the images and text on the screen. There are **3 types of monitor:** LCD, LED, and CRT. Newer version of monitor usually has **LCD (liquid crystal display)** or **LED (light-emitting diode)** these types of monito are usually thin and are often called **flat-panel display**. While older monitor use **CRT (cathode ray tube)** this type of monitor is much larger and heavier compared to the newer ones and they take up more desk space. - **KEY PARTS:** - **POWER CORD:** This is the link between your power outlet and the power outlet or supply of your computer. **UPS (uninterruptable power supply)** acts as a surge protector and provides temporary power if there is a blackout. - **KEYBOARD:** Use as one of the primary way of communicating with the computer and entering data. - **MOUSE:** Pointing device. **TYPES OF PERSONAL COMPUTER** - **DESKTOP COMPUTERS:** Can be small, medium, or large and normally sit on a desk. Commonly use at work, school, or library. - **LAPTOP COMPUTERS:** Laptops are battery or AC powered computers that are portable than desktop computers, allowing users to use them almost anywhere. - **SERVERS:** A server is a computer that serves up info to other computers on a network. Many businesses have file servers that employees use to store or share files. - **TABLET COMPUTERS** - **MOBILE PHONE** - **GAME CONSOLES** - **TV's** **COMPUTER BUG** - **"Grace Hopper"** found the first computer **"bug"** which is literally a bug or specifically a dead moth that had gotten into the Mark I and whose wings were blocking the readings of then holes in the paper tape. Since then the word "**bug"** had been used to describe defect since at least **1889** Hopper also credited with coining the word **"debugging"** which is the process of eliminating the program faults. **OPERATING SYSTEM (OS)** - The **most important software** that runs on a computer. Manages the computer's memory, processes, and all of its software and hardware parts. It also allows you to communicate with the computer without knowing how to speak the computer language. **Without the operating system the computer is useless** **EXAMPLE OF OS** - **MICROSOFT WINDOWS:** Created OS in the **mid-1980s**. Most current is WINDOWS 8 (2012), WINDOWS 7 (2009), and WINDOWS VISTA (2007). **Most popular operating systems.** - **APPLE MAC OS X**: Created by Apple Inc. Mcintosh computer or Macs. Latest ver. MAC OS X, specific ver. Include maverick (2013), Mountain lion (2012), Lion (2011), and Snow Leopard (2009). Also offered MAC OS X SERVER that runs on servers. - **LINUX:** An "**open-source"** os, which means they **can be modified and distributed by anyone around the world**. This is different from a **"closed-source**" propriety software like Windows, which **can only be modified by the company that owns it** (Microsoft). The advantage of Linux is that it is free, and there are several versions you can choose from. The most popular ones include Ubuntu, Mint, and Fedora. - **EXAMPLE OF OPEN AND CLOSED SOURCE:** - **OPEN:** Linux, FreeBSD, Opensolaris, Ubuntu, Haiku,etc. - **CLOSED:** Microsoft windows, MacOS, etc. **WHAT IS A POWER SUPPLY? AND HOW DOES IT WORKS?** - The power supply aka **power supply unit or PSU** is the **heart of the computer**. It provides electric power that is essential for powering the computer. The computer power supply converts the **AC** or alternative current **into** a specified **DC** or direct current. - **Modern PC** use **switch mode power supply unit or SMPSU.** This type of power supply **converts the incoming AC (alternating current) voltage to DC (direct current) without using a heavy mains transformer.** Instead, it uses electronic switching to rapidly turn the voltage on and off, creating a high-frequency square wave. This allows for a lighter and cheaper high-frequency transformer to produce the needed DC output. The output voltage and current are kept stable by a feedback controller, which adjusts the power output based on the load by changing the number of voltage pulses over time. **STANDARD OUTPUT VOLTAGES (12,-5,0,+3.3,+5,+12)** - **-12V:** Used on **older types of serial port amplifier circuits.** Generally unused or newer systems. Current is usually limited to 1A. - **-5V:** Used on some **early personal computers for floppy disk controllers and some ISA add-on cards**. Generally unused on newer systems. Current is usually limited to 1A. - **0V:** The zero-volt ground also called as common or earth and the reference point for other system voltages. - **+3.3V**: Used to supply power for the processor, some types of memory, some AGP video cards, and other digital circuits. - **+5V**: Still used to supply the motherboards. Note: that there is also 5V standby voltage present when the system is powered down which can be grounded to restore power to the system. - **+12V**: Primary used for devices such as disk drives and cooling fans which have motors of one sort or another. These devices have their own power connector that comes directly from the power supply unit. **COMMON PSU CONNECTORS** **P1:** A **ATX 20-pin or ATX 24-pin connector** that provides power to the motherboard. On some PSU's, the P1 is split into one 20-pin connector and one 4-pin connector (20-pin ATX connector, 4-pin ATX connector) which can be combined if required to form an ATX 24-pin connector. - **Blue =** -12V - **White =** -5V - **Black =** Ground - **Orange =** +3.3V - **Red =** +5V - **Yellow =** +12V - **Purple =** +5V standby - **Green =** DC on - **Brown =** Sense **ATX 12V (P4): A 4-pin power connector that goes to the motherboard** in addition to a 20-pin P1 to supply power to the processor. **MOLEX:** A 4-pin peripheral power connector that supplies power to the IDE disk drives and CD-ROM/DVD drives.  **BERG (MINI-MOLEX):** A 4-pin power connector that supplies power to the floppy disk drive. It can also be used as an auxiliary connector for AGP video cards.  **SATA OR SERIAL ATA:** A 15-pin power connector mainly used for SATA hard drives. **PCI EXPRESS:** 6-pin or 8-pin power connector used for PCI Express graphic cards. Some 8-pin connectors allow for either 6-pin or 8-pin card to be connected by using 2 separate connectors on the same cable. **POWER SUPPLY EFFICIENCY TABLE**  **CONCEPT DEVELOPMENT: BASIC HARDWARE COMPONENTS OF COMPUTER SYSTEM** A **CONTEMPORARY COMPUTER SYSTEM** consists of CPU, primary storage, secondary storage, input/output devices, and communication devices. - **PRIMARY STORAGE or MEMORY**: Stores the data and program temporarily while the CPU is processing it. Both of them consist of a chip that contains many microscopic pathways designed to carry electric current. There are **two types of memory volatile and non-volatile. Volatile memory** is lost when the computer power is off. While **Non-Volatile** memory on the other hand is not lost when power is remove from the computer. - **SECONDARY STORAGE or STORAGE DEVICES**: This stores the data and program permanently and are outside the computer. Ex. HDD, USB, CD, DVD. - **STORAGE MEDIUM**: This are physical material in which it stores data and program. Ex. Digi cam, memory cards. - **INPUT DEVICES**: This are devices that inputs data into your computer that the computer can use. Ex. Keyboard, mouse, microphone, scanner. - **OUTPUT DEVICES**: This is the processed input data or now known as information. Ex. Printer, monitor, speakers. - **COMMUNICATION DEVICES:** This provides communication between the computer and networks, which enables users to communicate and exchange data and info with other computers. This devices transmit the items over transmission media such as cables, telephone lines, satellites, and cellular radio. **PARTS OF A MOTHERBOARD** 1. **Back panel connector and ports:** This connects the computer to external devices such as display ports, audio ports, USB port, etc. 2. **PCI slots:** This is slot for older expansion cards. Ex. Sound card, network card. 3. **PCI Express x1 slots:** Slots for modern expansion cards and certain low-end graphics cards. 4. **PCI Express x16 slots:** This slot is for high-end graphics cards and high bandwidth devices. 5. **Northbridge:** This connects the CPU, PCI slot and RAM together. Also known as **MCH memory controller hub.** 6. **CPU Socket:** This is where you place the processor. 7. **ATX 12V Power Connector:** This helps the ATX power connector in supplying power to the CPU. 8. **Front Panel USB 2.0 Connectors:** Connects to the USB 2.0 port at the front or top of the computer case. 9. **Front Panel Connectors:** Connects to the power switch, reset switch, power LED, hard drive LED, and Front audio ports of the computer. 10. **IDE Connector:** Connects to older HDD and Optical drives for data transfer. 11. **CMOS Battery:** This is the one responsible for keeping the real-time running in your computer. This works once the computer is power off. 12. **South bridge:** Also known as ICH or Input/Output controller hub. Allows CPU to connect with the PCI's, SATA, USB, Ethernet, and on-board audio. 13. **SATA connectors:** Same as the IDE but this is the newer version. 14. **Fan Headers:** Serves as the cooling system of the system unit. 15. **Ram Slot:** Connects RAM to the motherboard. 16. **ATX Power Connector:** This powers the whole motherboard. **PARTS OF A SYSTEM UNIT** - **PSU or POWER SUPPLY UNIT:** This is the main power source of the computer in which it converts the 120V AC power to DC. - **MOTHERBOARD:** Also known as the backbone of the computer in which it connects all of the components. - **PROCESSOR OR CPU:** Also known as the brain of the computer. This is the one responsible for handing out all the instructions from software to hardware. It can also compute billions of mathematical formula in a span of seconds. - **RAM or RANDOM ACCESS MEMORY:** This is the short-term memory of the computer as it stores the data the CPU needs a quick access to. - **HDD or HARD DISK DRIVE (optional):** The long-term memory of the computer. The OS and all of the programs and data in your computer are stored here. **MEMORY AND STORAGE SIZES**  The system unit has two types of memory: volatile and nonvolatile. Volatile memory, like RAM, loses its data when the computer is turned off. Nonvolatile memory, such as ROM, flash memory, and CMOS, retains its data even when the power is off. - **1 KB or KILOBYTE = 1K BYTES, 1024** - **1 MB or MEGABYTE = 1M BYTES** - **1 GB or GIGABYTE = 1B BYTES** - **1 TB or TERABYTE = 1T BYTES** - **RAM** - **ROM:** Refers to memory chips that stores data permanently. ROM is usually nonvolatile. - **FIRMWARE:** Also a nonvolatile memory in which you can only read and use the data, but you cannot changed it. - **FLASH MEMORY:** Another type of nonvolatile memory is a chip that keeps it memory intact even if the power is shut off. - **CMOS**: Uses battery power to retain data when the computer is off. - **Expansion Slots**: Hold adapter cards to enhance system functions and connect peripherals. - **Flash Memory Cards & USB Drives**: Portable storage devices for various devices. - **Floppy Disks**: Outdated magnetic storage, replaced by modern methods. - **Hard Disk Drives**: Store data with internal and external components. **MASTER/SLAVE JUMPER SETTING** - **Master**: The main drive on the cable, or the first in a two-drive setup. - **Slave**: The second drive on the same cable. - **Master with non-ATA drive**: Use this if the main drive is paired with a CD-ROM or other non-hard drive. - **CS (Cable Select)**: Uses a special cable to automatically set drives as master or slave based on their position on the cable. - **Limit Capacity Option**: Use this if the computer can't handle the full size of the drive. **OTHER COMPONENTS: BUSES** Buses are electrical channels that allow different parts of a computer to communicate, similar to how vehicles travel on a highway. - **Types**: There are two main parts of a bus: - **Data Bus**: Transfers actual data. - **Address Bus**: Transfers information about where the data should go in memory. - **Bus Width**: Determines how many bits can be transmitted at once. Wider buses (e.g., 64-bit) transfer more data at a time, making the computer faster. - **Clock Speed**: Measured in megahertz (MHz), higher clock speeds mean faster data transmission, leading to quicker application performance. - **PC Card Slides**: A PC Card slides into a slot on the computer to add extra functions or connect to peripherals. **Types of Buses**: - **System Bus**: Connects the CPU to main memory on the motherboard. - **Expansion Bus**: Allows the CPU to communicate with peripheral devices. **Common Expansion Buses**: - **ISA Bus**: Old and slow, used for devices like mice and modems. - **PCI Bus**: Faster than ISA, used for video cards, sound cards, and network cards. - **PCI Express (PCIe) Bus**: Faster than PCI, used for modern video cards and hard disks. - **AGP Bus**: Designed for fast 3D graphics and video, used with AGP video cards. - **USB and FireWire Buses**: Connect devices outside the system unit without needing expansion cards. - **PC Card Bus**: Used for PC Cards, connects to the PCI bus. **PORTS AND CONNECTORS**: **Ports** are where a peripheral device (like a keyboard or printer) connects to the computer to send or receive data. **Connector** joins a cable to a port. Male connectors have one or more exposed pins; female connectors have matching holes. - **Types of Ports**: - **Serial Port**: Sends data one bit at a time, used for devices like mice and keyboards. - **Parallel Port**: Sends multiple bits at once, used for high-speed printers and other devices. - **USB and FireWire Ports**: Common for connecting various peripherals. - **Motherboard Ports**: Includes serial, parallel, USB, and FireWire ports. - **Adapter Cards**: Add extra ports to the computer.  **BIOS** The BIOS is a special software that interfaces the major hardware components of your computer with the OS. It usually stores in the flash memory chip on the motherboard, but sometimes the chip is another type of ROM. The BIOS uses CMOS to save the changes in the computer. **TOOLS AND EQUIPMENTS** - **PROTECTIVE EYEWEAR:** This protects the eye from particulates, infectious fluids, or chemicals. - **MULTI-METER or MULTI-TESTER:** Also known as VOM is an electronic measuring device that combines several measurement functions in one unit. - **PLIERS:** used to hold objects firmly, for bending, or physical compression. - **SCREWDRIVER:** A tool for driving screws and often rotating other machine elements with the mating drive system. - **SOLDERING GUN:** Is a tool for soldering metal. - **DESOLDERING TOOL:** Use for removing the molten solder. - **ALLEN WRENCH:** A tool of hexagonal cross-section used to drive bolts and screws that have hexagonal pocket. - **FLASHLIGHT:** The light source. - **IC INSERTION AND EXTRACTION TOOL:** Used for extracting and inserting BIOS chip. - **TWEEZERS:** Use for picking objects. - **ANTI-STATIC WRIST STRAP:** Used to safely ground a person working on a very sensitive electronic equipment. - **GLOVES:** Are garments for covering and protecting the whole hand. - **WINDOWS OPERATING SYSTEM CD/DVD:** An OS that is used as an intermediary between hardware and software. - **DEVICE DRIVER CD/DVD:** Application that used to install devices and peripherals. - **CRIMPLING TOOL:** Designed to crimp or connect the end of the cables. - **LAN TESTER:** Used for testing network cable connectivity. - **CABLE:** Used for computer networking. - **RJ 45 CONNECTOR:** A plastic connector used for UTP cable to connect computers in a network. - **ETHERNET SWITCH:** A switching hub that serves as the networking device that connects network segment or network devices.