Code Name Haswell Intel Next Generation Processor

Intel Corporation, a well known company that produces a lot of computer chipsets particularly microprocessors that runs our computers and various devices will be developing the Intel Next Generation Micro Architecture Code Name Haswell. It has been known that Intel Corporation is spending a lot of capital just to conduct research and experiment to develop a new technology that would aid other investors to make their gadgets products runs fast and durable. With durable and reliable gadget products you could attract consumers to promote and buy these gadgets.

Intel Next Generation Processor Code Name Haswell

Code Name Haswell Next Generation Intel CPU technology will probably introduce anytime this year during the IDF or Intel Developer Forum. Intel Developer Forum is an event held twice a year where in people from Technology Industry across the Globe gather and discusses latest advancement about Intel products. This year will be the most exciting since a numerous of Technical sessions will be hosted by Intel Corporation and   I believe that Code Name Haswell will be on top of the discussion.

Basic details about the significant improvements when it comes to performance, energy consumptions enhancement for graphics and support for a powerful new instructions for Code Name Haswell will be reveal. Haswell has been identified to compete with other vendors microprocessors that are currently used by other tablet PC’s. It is expected that you wouldn’t even differentiate the unit that is equipped with Haswell if it is running on stanby mode not, since energy efficiency is very much that great. If Intel will be successful for this so called New Intel Next Generation Code Name Haswell Processor, will this can alleviate issues in particular to notebooks and ultrabooks as well. Not to mentioned Desktop PC’s and Servers.

Acer Aspire V5-171-6867 Overview

Let's take a look for the Overview of this Excellent products produce by Acer Company; the New Acer Aspire V5-171-6867 a laptop powered by Intel third generation Core i5 Dual-core Processor with a speed of 2.6 Ghz. With its flashing speed you can open a bunch of applications without any worry of being end up into freezing issues. Wow! Adding a memory RAM of 6 GB and expandable up to 8 GB it feels like you are working with unlimited speed. An ultraportable gadget with a System weight of 2.98 pounds.

 Acer Aspire V5-171-6867 is equipped with 500 GB hard disk where-in you can save a bunch of files. This is suited to those people who are fan of saving HD movies and music. You can install a lot of applications that requires intensive disk space such as adobe applications and the likes. V5 has a pre-installed Operating System which is Microsoft Windows 7 Home Premium Edition 64-bit. However, you may upgrade the Operating System if you like just purchase another license of any Windows Edition.

The Video display is at 11.6 wide and this Acer Aspire V5-171-6867 can handle a video display resolution up to 1366x768 (HD) High Definition. The video chipset is powered by Intel HD Graphics 4000 with this video power; you can now play High Definitions video or HD and at the same time play a high intensive games with no worries when it comes to sluggishness. Added features are HDMI port where-in you can connect your HDMI devices; it has also a USB 3.0 port and Bluetooth.

How to Pass the TESDA NC II Computer Hardware Servicing Exam

Through my experience, passing the TESDA NC II Computer Hardware Servicing Exam is not really difficult as long as you follow these important tips. Be there at TESDA testing center earlier than the scheduled time for exam, eat well and avoid from any destruction. Once the exam started, listen very well on the instructions. Exam is divided into three categories theoretical, computer hardware identification, and practical exam.

Theoretical – is a written exam and it is composed of theories about computers such as computer terminologies, abbreviation, little of mathematical explanation like binaries and a lot more, so start reviewing your notes now. Computer Servicing Exam will also includes Networking Topologies advantages and disadvantages, network type of equipment will also be part on the exam. You must also review about the common types of viruses and how it will infect your computer system applications and operating system. Learning about various types of processors and its specifications is also a high value. You must also learn the BIOS Setup, and configuration, Operating System familiarization and likewise about storage devices. However, for theoretical they give a little weight for this exam since certification for TESDA NC II Computer Hardware Servicing is more focus on technical aspect so you must learn more about identifying parts of computers and its specific functions, as well as on the practical exam. There will be an instance that after the exam a discussion or some sort of interview between you and the examiner will be conducted.

Computer Hardware Identification – practically it is more on identifying computer parts and its function. From my experience, when I took the exam last two years ago they also included older computers to be part of the exam. During this exam you will be ask and explain a certain parts of computer. Computer modular parts are being placed on the table and randomly, the examiner will pick a computer parts and it will presented to you and it will ask you to identify the parts and explain the function of it. So it is really advisable to learn all parts of the computer in order for you to pass the computer hardware servicing exam.  For example; like Computer Mother Board or (MOBO) you need to identify what parts are included in the North Bridge and south bridge of this mother board. There are instances as well that old computer part will be ask to you such as; 8 bit and 16 bit ISA interface riser card, internal modem, com ports and serial ports. You may also ask to enumerate some of the input and output devices. In order to pass the hardware identification exam you must learn also the older parts of computers. One more tips, you might need also to learn about memory module it is possible that you will be ask the differences of various memory module types such as SIMM, DIMM, DRR 1, 2 and the latest is DDR 3. Also, you might learn computer beep error codes this is very important to identify computer hardware errors. Another thing is you need also to learn hard disk jumper settings and its purpose this is typically available on the PATA hard disk drive, this is in line in preparing your hard drive for OS installation.

Learn the Basic Networking and Topology

Computer Communications - A process in which two or more computers or devices transfer’s data, instructions, and information. For successful communications you need the following:

• A sending device - Initiates an instruction to transmit data, instructions, information
• A communications device - Connects the sending device to a communications channel
• A communication channel - Transmission media on which the data, instructions, or information 
• A communications device - Connects the sending device to a communications channel
• A receiving device - Accepts the transmission of data, instruction of information

Uses of computer communication

• Internet - A worldwide collection of networks that links millions of businesses, government agencies, educations, and individual
• Web - Worldwide collection of electronic documents on the internet that users access through Web browser.
• E-Mail - Or Electronic mail, is type of mail message that is sent through the network. 
• Instant messaging - A Real-time internet communication service that notifies you when one or more people are online,then allows you to exchange messages, pictures, files, audio and video.
• Chat rooms - A Real-time typed in conversation that takes place on a computer connected to a network, that also allows you to exchange messages, pictures, files, audio and video.
• Newsgroup - Online areas in which user’s have written discussion about a particular subject.
• Internet telephony - A conversation takes place over the internet using a telephone connected to a desktop computer.
• FTP - Internet standard that permits or allows user to upload or download files.
• Web Folder - Known as HTTP server, allows users publish documents and other files.
• Video conferencing - Realtime meeting over two person, use the internet to transmit audio and video signal.
• Fax Machine or Computer fax/modem - Transmits and receives documents over the phone line.

Network Communications Standard

Data is processed in one of two ways: Analog or Digital. A computer, by contrast, is Digital Which means it can process data in two discrete states: Positive (ON or 1) Non-Positive (OFF or 0). The 1 and 0 represent the two digits used by the binary number system, this system is at the heart of digital computing.

Computer Network - A collection of computers and devices connected together via communications devices and transmission media.

Preparing Hard disk for OS Installation

Here you will learn how to prepare your hard disk drive for operating system (OS) Installation. You must understand the process since this very essential when taking up TESDA NC II Computer Servicing Exam.


Partitioning - A procedure were the size of the harddisk is is being divided into several parts or space in preparation for formatting. Is a process of dividing the harddisk into regions called partition. Each partition occupies a group of adjacent cylinders. Partition allows you to organize a harddisk into segments or space in preparation for formatting.

FDISK - is the process of creating partitions into harddisk. Before you install your operating system, you must first create a primary partition on the hard disc (disc 1) in your computer, and then format the partition

Creating Partition Using FDISK for Windows ME and Windows 98

This process will need Windows ME/98 installation Disk or DOS bootable operating system diskette or CD. Once you run the bootable disk it will normally arrive to a:\> prompt. Normally when creating this kind of bootable disk it has the following tools needed. The fdisk.exe format.com. Once you are now on the command prompt just type in FDISK then it will now move on the process of creating partition. Just follow the steps below. 

• Creating DOS partition or Logical DOS Drive - Choose this option if you need to create a partition on your computer hard drive.
• Set active partition - If you have created multiple partitions on your hard drive choose this option to specify which partition you wish to set as active. When choosing option 2 to set the active partition, you will see a listing of the current partitions. Choose the number representing the partition you wish to set as active, the default is one.
• Delete partition or Logical DOS Drive - This option is used if you need to delete partition(s) from the computer's hard disc drive.
• Display partition information - Use this option to look at the current fixed disc drive partition information. If you have multiple drives you will need to choose option 5 before being able to display the other hard drive information.
• Display partition information - Use this option to look at the current fixed disc drive partition information. If you have multiple drives you will need to choose option 5 before being able to display the other hard drive information.

Hard Disk Jumper Settings Guide

Hard Disk drive jumper settings familiarization is also essential when taking exam for TESDA NC II Computer Servicing. Here you will learn how to set jumpers for hard disk depending on its purpose. Jumper settings will differ depending on the manufacturer so you must read the user maual before doing some configurations.

PATA Drives Configuration

Handling Precautions

• Disc drives are fragile. Do not drop or jar the drive. Handle the drive only by the edges or frame. Keep the drive in the protective anti-static container until you are ready to install it to minimize handling damage. 
• Drive electronics are extremely sensitive to static electricity. While installing the drive, wear a wrist strap and cable connected to ground. 
• Turn off the power to the host system during installation. 
• Do not disassemble the drive. Doing so voids the warranty. 
• Do not apply pressure or attach labels to the circuit board or to the top of the drive.

Operating System Familiarization

TESDA NC II Computer Servicing also requires the computer technicians to familiarize all types of operating system especially windows operating system. Here you can learn various types of operating system from first generation windows version up to the earlier time, and of course other well known operating system. In this example we are using Windows 2000 server, OS installation may differ in every version, however, sequence will be almost the same.

Operating System - (commonly abbreviated to either OS or O/S) is an interface between hardware and user; an OS is responsible for the management and coordination of activities and the sharing of the resources of the computer. The operating system acts as a host for computing applications that are run on the machine. As a host, one of the purposes of an operating system is to handle the details of the operation of the hardware.

List of Windows Operating System Version.

• Windows 3.0 is the third major release of Microsoft Windows, and was released on 22 May 1990. It became the first widely successful version of Windows.
• Windows 3.1x is a series of operating system produced by Microsoft for use on personal computers. The series began with Windows 3.1, which was vended first during March 1992 as a successor to Windows 3.0.
• Windows 95 is a consumer-oriented graphical user interface-based operating system. It was released on August 24, 1995 by Microsoft.During development it was referred to as Windows 4.0 or by the internal code-name Windows Chicago.
• Windows 98 (code-named Memphis) is a graphical operating system released on 25 June 1998 by Microsoft and the successor to Windows 95.
• Windows 98 Second Edition (often shortened to SE) is an updated release of Windows 98, released on 5 May 1999. It includes fixes for many minor issues, improved USB support, and the replacement of Internet Explorer 4.0 with the significantly faster and less error-prone Internet Explorer 5.0.
• Windows Millennium Edition, or Windows Me is a hybrid 16-bit/32-bit graphical operating system released on 14 September 2000 by Microsoft. It was originally codenamed Millennium.
• Windows 2000 is a line of operating systems produced by Microsoft for use on business desktops, notebook computers, and servers. Released on February 17, 2000,it was the successor to Windows NT 4.0, and is the final release of Microsoft Windows to display the "Windows NT" designation.
• Windows XP is a line of operating systems produced by Microsoft for use on personal computers, including home and business desktops, notebook computers, and media centers. The name "XP" is short for "experience". Windows XP is the successor to both Windows 2000 Professional and Windows Me, and is the first consumer-oriented operating system produced by Microsoft to be built on the Windows NT kernel and architecture.
• And currently, the latest Windows 7, Windows 8 which will be release by this coming October 2012, and of course Windows 2008 server version.

Learning About BIOS Setup

A ROM BIOS provides a built-in Setup program which allows the user to modify the basic system configuration and hardware parameters, Bios is a set of routines that affects how the computer transfer data between computer components, such as memory, disk, and the display adapter. The modified data will be stored in a battery-backed CMOS, so that the data will be retained even when the power is turned-off. In general, the information saved in the CMOS RAM will stay unchanged unless there is a configuration change in the system, such as hard drive replacement or a device is added. In this model we are using old type of BIOS version, looks will differ on some Machine model especially for the newer models.

Learn BIOS Menus and Other Features

STANDARD CMOS FEATURES / MAIN - allows you to record some basic system hardware configuration. 

• Time and Date Setting: to set, highlight Date /Time.
• This field records the specifications for all non-SCSI hard disk drives installed to   your system. The onboard PCI IDE connectors provide Primary and Secondary Channels for connecting up to four IDE hard disk or IDE devices (CDROM’S, DVD ROM, DVD WRITER, CDWRITER’S, ZIP DRIVES). Use the Auto setting for detection during boot up.
• Drive A / Drive B (none)* this field records the type of floppy drives installed in your system. The available options for drives A and B are 360KB, 5.25 in.; 1.2 MB, 5.25 in.; 720kb, 3.5 in.,1.44MB; 3.5 in., 2.88 MB, 3.5 in.; None. (Floppy 3 Mode Support (disabled)* This is a Japanese standard floppy drive, no need to enable.)
• Video (EGA/VGA)* Set this field to the type of video display card installed in you system. Options are EGA/VGA, CGA 40, CGA 80, and mono( for Hercules or MDA).
• Halt On (All Errors)* This fields determines which types will cause the system to halt. Choose from either All Errors; No Errors; All, But Keyboard; All but Diskette; or All, But Disk/Key.
• Control keys with their respective functions, used to change the values of the CMOS SETUP.

System Unit Disassembly Procedure

This is one of the most important things to learn in taking the TESDA NC II Computer Servicing Exam. You need to learn the step by step procedure on how to open and disassemble a system unit. There are various design of computer casing and before opening you need to check and see how you will start the system unit dis-assembly. Here we are going to use a mini-tower casing as our model, mini-tower casing design is the most easiest to disassemble, however that would depend on the brand and model.

• It's Not a Race, take a slow relaxed approach, discuss, question and research each component as it's removed.
• Fall back on your own knowledge, use the Internet, your books and resource material. It's impossible to retain all the information, so one of the most important computer skills you can learn is how to research and use your resources to find what you need.

Questions to Think About or Discuss as you Disassemble

• Should I document everything I do or everything I remove?
• Am I taking the best ESD precautions available to me right now?
• When you remove an expansion card what kind of card is it?
• When removing a drive, what kind of drive is it?
• When removing wires or cables, what are the cables for?
• Am I still taking proper ESD precautions and is my anti-static strap still hooked up?
• Look at the motherboard again when there's not so much in the way. Can you point out the CPU?

Before You Begin

                       

• Have a pen and paper ready. Documentation is real important.
• Make sure you have the tools you need and they're all close by and handy.
• Be sure to have a container to keep the screws in.
• Make sure you have the resource material, drivers or software that you may need.
• If possible, enter the CMOS setup and record the information available.
• Disassembly is major surgery, do a full backup of the system.

Examples of Input and Output Devices

What is an Input Devices - An input device is any hardware component that allows you to enter data and instruction into a computer.

Examples of Input Devices

• Keyboard
• Mouse
• Image/Object scanner
• Microphone
• Joysticks, Game pads
• PC video camera
• Digital camera
• Bar code scanner
• Biometric scanner

Input Devices

What is an Output Devices - An output device is any hardware component that conveys information to one or more people.

Examples of Output Devices

• Monitor
• Printer
• Speaker

Identifying Expansion Module Cards

Expansion Card - Is a printed circuit board that can be inserted into an expansion slot of a motherboard to add additional functionality to a computer system. One edge of the expansion card holds the contacts (the edge connector) that fit exactly into the slot. They establish the electrical contact between the electronics (mostly integrated circuits) on the card and on the motherboard.The primary purpose of an expansion card is to provide or expand on features not offered by the motherboard.

VGA Card

Video cards or VGA Cards - The video card is an expansion card that allows the computer to send graphical information to a video display device such as a monitor or projector.

Sound Card

Sound card - Is a computer expansion card that facilitates the input and output of audio signals to and from a computer under control of computer programs. Many computers have sound capabilities built in, while others require additional expansion cards to provide for audio capability.

NIC Card

NIC (Network interface card) - A network interface card, more commonly referred to as a NIC, is a device that allows computers to be joined together in a LAN, or local area network. Networked computers communicate with each other using a given protocol or agreed-upon language for transmitting data packets between the different machines, known as nodes.

Modem Card

Learn About Storage Devices

Storage device - is a hardware device designed to write and read information. There are two types of storage devices used in computers; a 'primary storage' device and a 'secondary storage' device.

Storage Media - It is where the storage device records (write) and retrieves (read) the data, instructions and information for future use.

Examples of Storage and Media Devices

Harddisk Devices and USB Thumb Drive

Optical Device

3.5 Floppy Device

Identifying Memory Module

Memory Module - A device that are used to store data or programs (sequences of instructions) on a temporary or permanent basis for use in an electronic digital computer.

• Volatile memory is computer memory that requires power to maintain the stored information.
• Non-volatile memory is computer memory that can retain the stored information even when not powered.

Types of Memory Module

30 Pin and 72 Pin SIMM Module

DIMM - SDRAM Single Data Rate

DDR - Double Data Rate

Learn About Central Processing Unit

Learning about central processing unit is also part of the TESDA NC II Computer Servicing exam. So it is advisable to learn about these things.

Processors

Central Processing Unit - Is a complete computation engine that is fabricated on a single chip. Interprets and carries out the basic instructions that operate a computer. Processors contain a control unit and an arithmetic logic unit (ALU), this two components work together to perform processing operations.

Dual-Processor

Dual-processor (DP) - systems are those that contain two separate physical computer processors in the same chassis. In dual-processor systems, the two processors can either be located on the same motherboard or on separate boards.

Dual Core Configuration

Dual-core configuration - an integrated circuit (IC) contains two complete computer processors. Usually, the two identical processors are manufactured so they reside side-by-side on the same die, each with its own path to the system front-side bus.

Dual core Processor features: 

• Hyper-Threading Technology: Enables you to run multiple demanding applications at the same time.
• Intel Extended Memory 64 Technology: Provides flexibility for future applications that support both 32-bit and 64-bit computing.
• Dual-Core: Two physical cores in one processor support better system responsiveness and multi-tasking capability than a comparable single core processor.

Processor core (An intel Core 2 Duo Chip) It has 291,000,000 transistor.

Identifying Motherboard Hardware Parts and its Function

The motherboard is considered as the main circuit of the computer, it contains the connectors for attaching additional boards. Typically, the motherboard contains the CPU, BIOS, memory, mass storage interfaces, serial and parallel ports, expansion slots, and all the controllers required to control standard peripheral devices, such as the display screen, keyboard, and disk drive. Collectively, all these chips that reside on the motherboard are known as the motherboard's chipset. You must familiarize the motherboard parts and its function since this is needed to pass the TESDA NC II Computer Servicing Exam. 

Parts of the Mother Board

Computer System Error Beep Codes

Power On Self Test Beep Codes

The computer POST (Power On Self Test) is the process of testing the computer system, insuring that it meets the necessary system requirements and that all hardware is working properly before starting the remainder of the boot process. If the computer passes the POST, the computer will have a single beep (with some computer BIOS manufacturers it may beep twice) as the computer starts and the computer will continue to start normally. However, if the computer fails the POST, the computer will either not beep at all or will generate a beep code, which tells the user the source of the problem.

Each time the computer boots up the computer must past the POST. Below is the common step a POST performs each time your computer starts.

1. Test the power supply to ensure that it is turned on and that it releases its reset signal.
2. CPU must exit the reset status mode and thereafter be able to execute instructions.
3. BIOS checksum must be valid, meaning that it must be readable.
4. CMOS checksum must be valid, meaning that it must be readable.
5. CPU must be able to read all forms of memory such as the memory controller, memory bus, and memory module.
6. The first 64KB of memory must be operational and have the capability to be read and written to and from, and capable of containing the POST code.
7. I/O bus / controller must be accessible.
8. I/O bus must be able to write / read from the video subsystem and be able to read all video RAM.

If the computer does not pass any of the above tests, your computer will receive an irregular POST. An irregular POST is a beep code that is different from the standard one or two beeps. This could be either no beep at all or a combination of different beeps indicating what is causing the computer not to past the POST.

Example of a Computer Error Beep Codes

Beep Code	Description of Problem
No Beeps	Short, No power, Bad CPU/MB, Loose Peripherals
One Beep	Everything is normal and Computer POST is fine
Two Beeps	POST/CMOS Error
One Long Beep, One Short Beep	Motherboard Problem
One Long Beep, Two Short Beeps	Video Problem
One Long Beep, Three Short Beeps	Video Problem
Three Long Beeps	Keyboard Error
Repeated Long Beeps	Memory Error
Continuous Hi-Lo Beeps	CPU Overheating

Common Types of Computer Viruses and How it Infect

You will learn here the Common types of Viruses and how it will infect your Computer System Unit.

Trojan Horses - like their namesake, try to tempt or trick the user into activating the program themselves. They have innocent names, like ‘IMPORTANT.EXE’, README.EXE’,’URGENT.EXE’, or appear to be a game or application. The user clicks on them and releases the payload.

Worm Viruses - Usually found on intranets or Internets, these files would gather information as they sat on the system. Maybe recording passwords or access codes when they were typed in, or leaving ‘back doors’ open, allowing for authorized accesses. Another type of worm virus is a file that just keeps replicating itself over and over. By constantly reproducing itself it can slow a computer or an entire network to a standstill.

All these types of miscreant software are often lumped together and called viruses. And, a lot of viruses do contain these in some form or another. However, a true virus usually has a ‘host’ file. In other words, it can attach itself to a file already on your system. It has the ability to clone itself. It can reproduce itself and infect other files or drives and computer systems. Viruses can also hide themselves from detection in several different ways.

How Viruses Avoid Detection

Encryption - Virus detection programs will look for programming code that allows programs to replicate or clone. This is one way that it searches for and recognizes possible viruses. Using encryption, virus programs can change from replication code and back, trying to avoid this type of detection.

Polymorphism - Another way that a virus can be detected is by its signature. Each virus has a signature, or a piece of code that is specific to that individual program. Virus detection programs look for these signatures when scanning the files on your drive. Polymorphic viruses are created with the ability to change their signature each time they clone or reproduce.

Stealth - Detection programs note the characteristics of files and watch for any changes, which might indicate infection. When a Stealth virus infect a file, it can modify the characteristics of that file so that it still reports that same date, time, checksum, and size. It can also monitor the Operating systems call for a file and remove itself temporarily, or load an uninfected copy of the file that it has made for just that purpose.

Viruses Targeted Mainly the Following

Boot Sector Viruses - write themselves into the Boot Sector of a Hard or Floopy Diskette. Every disk has a boot partition that contains coded information.The hard drive has a Master Boot Record that contains partition information as well as another boot record for the operating system. The boot sector on bootable floppy disk contains that code necessary to load the operating system files. The boot sector on a non-systems disk contains the information that will display the message ‘Non-systems disk or disk error, remove and press any key when ready’. The boot sector of an infected floppy contains the coding that will infect the hard drives partition sector.

If an infected floppy is left in the drive at boot up, it loads the virus into memory and copies itself to the partition sector of the hard drive. Now, every time the computer is booted from the hard drive, the virus in

Various Testing Performed on a Computer System

To be able to pass the TESDA NC II Computer Servicing Exam you need also to learn about Various Testing procedure performed on a computer System. System testing of software or hardware is testing conducted on a complete, integrated system to evaluate the system's compliance with its specified requirements. As a rule, system testing takes, as its input, all of the integrated software components that have successfully passed integration testing and also the software system itself integrated with any applicable hardware system(s). The purpose of integration testing is to detect any inconsistencies between the software units that are integrated together (called assemblages) or between any of the assemblages and the hardware.

The following examples are different types of testing that should be considered during System testing:

GUI SOFTWARE TESTING

Is the process of testing a product that uses a graphical user interface, this is to ensure that it meet its written specifications. This is normally done through the use of a variety of test cases. Most clients in client/server and web-based systems deliver system functionality using a GUI. When testing complete systems, the tester must grapple with the additional functionality provided by the GUI. GUIs make testing systems more difficult for many reasons: the event-driven nature of GUIs, unsolicited events, many ways in/many ways out and the infinite input domain problems make it likely that the programmer has introduced errors because he could not test every path.

               

Graphical user interface is a type of user interface which allows people to interact with electronic devices such as computers; hand-held devices such as MP3 Players, Portable Media Players or Gaming devices; household appliances and office equipment with images rather than text commands. A GUI offers graphical icons, and visual indicators, as opposed to text-based interfaces, typed command labels or text navigation to fully represent the information and actions available to a user. The actions are usually performed through direct manipulation of the graphical elements.

Computer Hardware Servicing Safety and Precautions

TESDA NC II Computer Servicing also requires to learn about the Computer Hardware Servicing Safety and Precautions. The only danger to you in most of these devices is the AC line connection. Before you plug in the unit with any covers removed, make note and cover up any exposed AC line connections.  The rest of the circuitry is low voltage and while you can destroy your equipment by your actions, you should be fairly safe. The following SafetyGuidelines are included for your survival when working on line connected or high voltage equipment.

• Don't work alone - in the event of an emergency another person's presence may be essential.
• Always keep one hand in your pocket when anywhere around a powered line-connected or high voltage system.
• Wear rubber bottom shoes or sneakers.
• Don't wear any jewellery or other materials that could accidentally contact circuitry and conduct current, or get caught in moving parts. (Bracelets, long necklaces)
• Don't attempt repair work when you are tired.  Not only will you be more careless, but your primary diagnostic tool - deductive reasoning - will not be operating at full capacity.
• Finally, never assume anything without checking it out for yourself!  Don't take shortcuts!