Tuesday, January 24, 2017

Computer Parts and Their Uses






Basic parts and functionality of the computer

Whether it is a telephone with a touch screen, a laptop, a tablet or a desktop, all computers consist of certain basic elements. This basic assembly is formed usually of a motherboard, a processor, central memory, hard disc drive, connections, the monitor as well as the keyboard, mouse or some kind of a touch pad. The majority of the listed parts are inside the cabinet, but knowing them is important in order to manage different problem situations.

The computer case

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The computer case contains the most important components of the computer: the motherboard, the processor, random access memory modules, the hard drive etc. It may not be possible to exchange the components in a laptop computer, but in a desktop computer you have much more influence on the parts inside the cases.

The motherboard

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The motherboard is the part of the computer where such things as the processor, memory modules, expansion cards and external devices are attached. This means that the motherboard controls the functions of different components. The number of connection slots for peripheral devices and the number and type of memory slots are important properties of the motherboard. In addition to the various connections, the motherboard also has a small battery ensuring that settings made on the board are retained even when the computer is switched off.

The processor



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The processor can be considered to be the ‘engine’ of the computer because it executes the lion’s share of the information processing; the processor fetches commands and necessary information from the RAM, carries out the tasks specified by the commands, and returns the processed information to the RAM. The speed of a computer depends largely on the speed of the processor. The processor’s speed, in turn, is affected by various factors, such as the so-called clock frequency (usually expressed as gigahertz, GHz), the number of cores and of the so-called cache memory inside the processor.

Random access memory



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The RAM (Random Access Memory) is a memory storage that functions during computer use and is especially utilized by the processor. In modern computers, the amount of RAM is around 4 – 16 GB depending on the type and purpose of the computer (please see data measurement units for more information). The RAM consists of one or more memory modules (see image above). When the computer is started, the operating system is loaded into the RAM (an operating system is a program that controls the devices and programs in a computer – please see operating systems for more information). The computer also loads the files being processed – music, assignments, videos etc. – to the RAM. If there is enough RAM, the computer executes requested tasks quickly. This is why it is a good idea to add to the memory by buying more memory modules as the need arises.







Hard drive



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The hard drive is the permanent memory of the computer where saved files remain even when the computer is turned off. This is why the hard drive is used for saving files. The capacity of hard drives varies; currently the typical capacity is 500-1000 GB, but hard drives of over 1500 GB, i.e. 1,5 terabits, are also available. However, the capacity of the internal hard drives in laptop computers is often less than that. You can add to the capacity of your computer by attaching an additional hard drive, either internally or externally. More information about storage sizes can be found here.

The hard disk is used for the storage of the computer’s operating system and all important files. It is therefore packed in a fixed protective housing. The disks may become damaged in spite of this protection, so you should absolutely make backup copies of files on the hard drive from time to time (please see backup copies for more information)!



DVD and Blu-ray drives with writing capabilities



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Most computers these days come with a  Blu-ray drive or a DVD (Digital Versatile Disk) drive with writing capabilities, with which you can burn such things as backup copies of important files to DVDs. CD drives are older and have mostly been replaced with DVD drives. CD drives can only burn data on CDs, which have a substantially smaller storage capacity, while DVD drives can burn data to both CDs and DVDs with more capacity (please see recording media for more information).



The display and display adapter



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Most computer displays are so-called LCD displays (Liquid Crystal Display), where the image display is produced by liquid crystals between two transparent sheets. Display sizes range between only a few inches in handheld apparatuses to large 24 inch desktop displays. One of the most important features of the display is its resolution, i.e. how many pixels (picture elements) the image consists of.  A normal 22 to 24-inch widescreen display usually has 1920 pixels horizontally and 1200 pixels vertically (1920×1200). These displays can reproduce Full HD (full high definition) image. No matter what the type of display is, the computer must contain a so-called display adapter that allows you to attach the display to the computer and controls the display image. Practically all motherboards come equipped with a display adapter, so you do not need to buy one separately, unless you want to enhance the capabilities of your desktop computer e.g. for gaming, video editing, or 3D imaging purposes.



Keyboard

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A standard keyboard has 102 keys. The keys are divided into alphabetical (a-z), numerical (1-0) and special (Function, Ctrl, Alt etc keys). In addition to the usual alphabetical and numerical keys, you should know at least the following special keys that are located among the alphabetical ones. Below are shown some typical keys on a PC keyboard. The keyboard mapping on Mac computers is almost identical to PC keyboards, but the special keys Ctrl and Alt work slightly differently. In addition, the Mac keyboard has Fn and Cmd keys instead of the Windows key.






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Ctrl: (Control) is used in combination with other keys for different actions. The combination Ctrl+C, for example, copies the chosen data to the memory.
Alt: (Alternative) is used like the Ctrl key. Sometimes both these keys are used in combination: Ctrl+Alt+Del, for example, brings up the task manager(in Windows XP).
Alt Gr
: (Alternative Graphics) produces the ‘third character’ of the keys, e.g. @, $, £ and }. With this key, you can also create the ~ character (important for the internet). Create the  ~ character as follows: press ALT-GR and the ~ key at the same time, and finish with the space bar.
You can make so-called ascii characters with combinations of the Alt key and numerals, e.g. Alt+0176 makes the character for temperature °. You can choose to either add special characters in this way or through an application. Most text processing programs have their own menu for special characters.
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Shift: capitalizes letters and the special characters on the numerical keys, among others.
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Caps Lock: locks the capitalization of letters. This function is connected with an A or Caps lock pilot light on the keyboard. It turns on the light when the function is in use.
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Tab: the tabulator is mainly used in word processing: each time you press the tab button, the cursor moves to the next tab stop on the same row. The key can also be used for alternating between window displays.
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Backspace: removes the characters to the left of the cursor, i.e. what you just wrote. This key can also be used to remove a larger portion of text.
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Enter: by pressing this key you can change paragraphs or e.g. accept a function.

There are more special keys above the alphabetical keys; of these the function keys (please see next image) are used for different functions, depending on situation and the program currently being used. The manual for these functions is usually available in the manual for the program.

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To the left and right of the function keys, you will find the following additional keys:

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Esc (Escape): mostly used to cancel a function, or e.g. to close a menu window.
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Home and End: these keys bring the cursor to the top or the bottom of the line.
Page Up and Page Down: move the page up or down.
Insert: starts the insert function, where the text you are writing replaces the text to the right of the cursor.
Delete: deletes the character to the right of the cursor.
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Arrow keys: move the cursor in the direction shown by the arrows.
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The number pad is activated with the Num Lock key: when it is activated, the pilot light with the symbol 1 or the text Num Lock lights up. Usually the Num Lock function has been set to be turned on when starting up the computer. If the pilot light is not turned on, the keys function in the way indicated by the symbols on the keys (8 up, 4 left, 6 right, 2 down).

The keyboard also has the rarely used keys Print ScreenScroll Lock and Pause. The Print Screen key lets you take a picture of the display (Alt+PrintScreen takes a picture of the currently activated window) and send it to your clipboard, Scroll Lock locks the scrolling of the display and the Pause key can be used e.g. for stopping the loading of the system during start-up.

For more information on hotkeys and key combinations, see the additional reading material.

Pointing devices

Traditionally, most programs have been designed to be used with a mouse. The mouse cursor seen on the screen of the computer moves along with the mouse.  The cursor can be used to select menu commands and areas, as well as activating different objects by clicking the mouse keys.


Mouse

You can attach a traditional mouse with or without a cord to any computer. Cordless mice use radio waves to relay movement from the mouse to the computer (for this mouse, a small radio receiver is attached to the computer).

Touchpad

Almost all laptop computers have a touchpad which is used to move the cursor. Some models also have a so-called pointing stick. In addition, portable computers have keys with the clicking function of mouses. The  touchpad is a pad where you can control the cursor by moving your finger along the pad. Tapping the pad serves the same function as clicking a mouse.

Pointing stick

The pointing stick is a ‘nub’ located in the middle of the keyboard, and controls the cursor. The pointing stick can be ‘clicked’ by tapping the stick or using the separate buttons in the keyboard. In the right-hand image above, you can see a portable computer with both a pointing stick (blue) and a touchpad (the large, dark grey area in front of the keyboard).

Touchscreen

Devices that are smaller than a laptop, such as phones and tablets, usually do not have a separate keyboard or pointer device. In these devices, the entire screen of the device works as an input device. A touchscreen is used like the track pad on a laptop, and when typing is required, a keyboard appears on the screen.

Procedures in Cleaning, Tightening and Simple Repair of Hand Tools, Equipment and Paraphernalia

Procedures in Cleaning, Tightening and Simple Repair of Hand Tools, Equipment and Paraphernalia

The proper use of tools, equipment and paraphernalia will greatly increase efficiency and occupational safety in a workplace. Having the proper knowledge and skills in using such tools is needed in order to operate and use them effectively. But more often than not, problems and malfunctions may arise while using these tools. These malfunctions can be minimized by exercising careful usage of the tools.
Malfunctions and other unplanned and unusual event may not be totally eliminated, but it can surely be minimized.
Listed below are some of the malfunctions and unplanned events when using the different tools in completing a job requirement:
·         When using a driving tool, screws may slip the tip of the screw driver. This happens when the screw driver is not properly aligned with drive of the screw’s head. This can be minimized by making sure that the tip of the screw driver is well secured in the drive of the screw’s head. Using a screw driver with a magnetized tip can also help minimize this type of malfunction.
·         Small objects tend to fall down when being held by a gripping tool like pliers. This usually happens when the jaws of the pliers are blunt, thus making it hard to hold on things. This can be prevented by making sure that gripping tools have well maintained jaws that can grasp objects properly.
Listed below are some of the malfunctions and unplanned events when using the different tools in completing a job requirement (continued):
·         The use of striking tools also imposes a great threat if there will be a malfunction. Common hazards are heads separating away from the handle. This could cause severe injuries to anyone. To avoid this type of accident, the handle of a striking tool must be tightly attached to its head.
·         Mishaps in using cutting tools is also dangerous. Malfunctions may arise from slippage of the material to be cut. This may also happen if a cutting tool is not sharp enough. These unplanned events will cause laceration and wounds to the user. To avoid this, cutting tools must always be kept sharp.
·         Power tools also impose danger during mishaps. Common problems are electrical short circuiting or mechanical problems. Malfunctioning power tools may cause electrocution and even decapitation of the limbs. These accidents can be avoided by making sure that all power tools are well maintained and are in fit operating condition.
·         Diagnostic tools may not impose a threat to the well-being of a worker but inaccurate reading may compromise the completion of a job requirement. Inaccurate reading may occur if a diagnostic tool is not properly calibrated. To avoid this, a regular calibration to all diagnostic tools must be done.
REMEMBER:
·         There is certainly no absolute way to avoid any unforeseen malfunctions.
·         The only way to minimize them is to have the appropriate knowledge in using the different tools.
·         Proper inspection and assessment of tools must also be practiced to ensure the safety of the worker and the accurate completion of a job requirement.
·         Having a first aid kit in the work area is also necessary so that quick response and cure can be applied in case of any injuries.
Source: https://school.quipper.com/en-PH/index.htm



Thursday, January 12, 2017

Tools for computer hardware servicing



            

                       ESD Tools




                                              




Antistatic wrist strap: Protects computer equipment when grounded to a computer chassis.













Antistatic mat: Protects computer equipment by preventing static electricity from accumulating on the hardware or



                   

         Hand Tools

Most tools used in the computer assembly process are small hand tools. They are available individually or as part of a computer repair toolkit. Toolkits range widely in size, quality, and price. Some common hand tools and their uses




 

Flat-head screwdriver: Used to tighten or loosen slotted screws.










       Phillips-head screwdriver: Used to tighten or loosen cross-headed screws.










 Torx screwdriver: Used to tighten or loosen screws that have a star-like depression on the top, a feature    that is mainly found on laptops.











Hex driver: Used to tighten or loosen nuts in the same way that a screwdriver tightens or loosens screws  (sometimes called a nut driver).



  








Needle-nose pliers: Used to hold small parts.













Wire cutters: Used to strip and cut wires.








                                                          
                                                     
       
Tweezers: Used to manipulate small parts.














Flashlight: Used to light up areas that you cannot see well.













 

Wire stripper: A wire stripper is used to remove the insulation from wire so that it can be twisted to other wires or crimped to connectors to make a cable.













Crimper: Used to attach connectors to wires.











Punch-down tool: Used to terminate wire into termination blocks. Some cable connectors must be connected to cables using a punch down tool.





          

          Cleaning Tools

Having the appropriate cleaning tools is essential when maintaining and repairing computers. Using the appropriate cleaning tools helps ensure that computer components are not damaged during cleaning. Cleaning tools include the following:





Soft cloth: Used to clean different computer components without scratching or leaving debris













Compressed air: Used to blow away dust and debris from different computer parts without touching the components


















Cable ties: Used to bundle cables neatly inside and outside of a computer












Parts organizer: Used to hold screws, jumpers, fasteners, and other small parts and prevents them from getting mixed together



            



Diagnostic Tools







Digital multimeter: is a device that can take many types of measurements. It tests the integrity of circuits and the quality of electricity in computer components. A digital multimeter displays the information on an LCD or LED.











Loopback adapter: is also called a loopback plug, tests the basic functionality of computer ports. The adapter is specific to the port that you want to test.











Toner probe:The toner part is connected to a cable at one end using specific adapters, such as an RJ-45, coaxial, or metal clips. The toner generates a tone that travels the length of the cable. The probe part traces the cable. When the probe is in near proximity to the cable to which the toner is attached, the tone can be heard through a speaker in the probe.