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2012-06-30

A+: Where to Go for More Information

After you’ve gathered as much information as possible, you might find that you still need more help. User manuals for components often are discarded, software drivers need to be updated, and some conflicts don’t have easy answers. Use the following resources for more help:
• Manufacturers’ websites— Most system and component manufacturers provide extensive technical information via the World Wide Web. You’ll want to have the Adobe Reader program in its latest version available to be able to read the technical manuals you can download (Adobe Reader itself is a free download from www.adobe.com). These sites often contain expert systems for troubleshooting, specialized newsgroups, downloadable driver updates, and other helps for problems.

• Printed manuals— Although many vendors have switched to web-based or Adobe Reader (PDF) manuals, some vendors still provided printed manuals or quick-reference diagrams. Be sure to file these in a way that permits quick access when needed.
• Web-based or PDF manuals on disc— Many vendors, especially those that use CDs or DVDs to distribute device drivers or utility programs for hardware, now put their user or reference manuals on the same medium. To view a web-based manual, open the file with your web browser. To view a PDF manual, open the file with Adobe Reader, Adobe Acrobat, or other PDF viewer/editor.
• Help for “orphan” systems and components— It’s frustrating to need information about a system whose manufacturer is no longer around. Sites such as http://www.download.com and www.windrivers.com provide information and drivers for orphan systems and components.
• Online computer magazines— If your back-issue collection of major computer magazines is missing some issues, or even if you’ve never subscribed to the print versions, you can find a lot of technical content from the major magazine publishers online: www.pcmag.com (PC Magazine), www.pcworld.com (PC World), and www.maximumpc.com (Maximum PC) are just three of my favorite resources.
• Third-party news and information sites— Tom’s Hardware (www.tomshardware.com), AnandTech (www.anandtech.com), The Register (www.theregister.co.uk), and iXBT Labs (http://ixbtlabs.com/) are just a few of the websites I rely on for product reviews, news, and insights.
• Book series— Scott Mueller’s Upgrading and Repairing PCs (www.upgradingandrepairingpcs.com) can be a lifesaver. With over 2.2 million copies sold, it’s still the single best source of information about desktop computer hardware, old and new. Other books in the series, such as Upgrading and Repairing Laptops and Upgrading and Repairing Windows, Second Edition, are also valuable. The Upgrading and Repairing Networks text is recommended for improving your network skills. When it comes to Windows, try Que’s Special Edition Using and In Depth series (www.quepublishing.com).
• Search engines— Google (www.google.com), Yahoo! (www.yahoo.com), Goodsearch (www.goodsearch.com), Bing (www.bing.com), and others and aggregators such as 
locate specific resources for further research. Currently, of these, my favorite is Google. Google is fast, finds text in many types of online content (not just HTML web pages, but also Adobe Acrobat, Microsoft Word, and others), can search newsgroups, and finds image and video files as well. Use its Advanced Search feature to narrow your search; you can even search a particular website only. Click the Cached button to see the site as Google last saw it if the current contents aren’t what you need or the website is down. Go to http://groups.google.com to search or browse Usenet newsgroups.
With so many sources of information available in print and online, there’s no reason to stop learning. To succeed and enjoy yourself, take every opportunity to learn more.







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A+: Best Sources for Replacement Parts, and Keeping Track of Solutions

“Known-Working” Doesn’t Mean “New”

To perform parts exchanges for troubleshooting, you need replacement parts. If you don’t have spare parts, it’s very tempting to go to the computer store and buy some new components. Instead, take a spare system that’s similar to the “sick” computer, make sure that it works, and then use it for parts. Why? Just because it’s new doesn’t mean it works.
I once replaced the air conditioning compressor on my van with a brand-new, lifetime-warranty alternator that failed in less than a week, and six more replacements failed (all from the same batch or defective parts). Whether it’s a cable, a video card, a monitor, or some other component, try using a known-working item as a temporary replacement rather than brand-new.
Rather than give away, sell, or discard working video cards, hard disks, and other components you have replaced with faster, bigger, better upgrades, keep at least one of each item to use as a replacement for testing purposes or as a backup in case the upgrade fails.
If you don’t have spare parts, use a spare system if possible rather than knocking another working system (and user) out of action by “borrowing” parts from an operational system. Use the same brand and model of system for known-working spares if possible, because the components inside are more likely to be identical to the “sick” system you are diagnosing.
Swapping from an identical or nearly identical systems is especially important if the system you are diagnosing uses proprietary components or is a laptop computer.

Keeping Track of Your Solutions

 
Make a practice of keeping detailed notes about the problems you solve. If your company has a help-desk system with tracking capabilities, use it. Even if the best you can do is write up your findings, you can use desktop search tools to find the answers to the same problems that might arise later.
Be sure to note symptoms, underlying problems, workarounds, and final resolutions. To help capture the information you need:
• Use Windows’ Screen Capture feature (press the PrtScn button and copy the clipboard contents into Paint or another image editor) to grab screens.
• Use the Save As Web Archive feature in Internet Explorer to grab web pages complete with text and links as one file.

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A+: Points of Failure on the Outside of the Computer

The front of the computer might provide valuable clues if you’re having problems with a system. In case of problems, check the following common points of failure for help.
Can’t read CD or DVD media— The drive door on the CD-ROM or other optical drive might not be completely closed or the media might be inserted upside down; press the eject button to open the drive, remove any obstacles, reseat the media, and close the drive.
You can also eject optical media with Windows Explorer/My Computer. Right-click the drive and select Eject. If the drive doesn’t eject the media, there could be a problem with the drive’s data cable, cable connection, or power connection.
Can’t shut down the computer with the case power switch— The case power switch is connected to the motherboard on ATX, BTX, and other modern desktop systems, not directly to the power supply as with older designs. The wire might be loose or connected to the wrong pins on the motherboard. Keep in mind that most systems require you to hold in the power button for about four seconds before the system will shut down. If the computer crashes, you might need to shut down the computer by unplugging it or by turning off the surge suppressor used by the computer. Some ATX and BTX power supplies have their own on-off switches.
Can’t see the drive access or power lights— As with the case power switch, these lights are also connected to the motherboard. These wires might also be loose or connected to the wrong pins on the motherboard.
Can’t use USB, IEEE-1394, or other ports on the front of the system— Some systems have these ports on the front of the computer as well as the rear. Front-mounted ports are connected with header cables to the motherboard. If the cables inside the case are loose, the ports won’t work. If the ports are disabled in the system BIOS, the ports won’t work.

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A+: What Components to Check First

As the previous subsystem list indicated, there’s no shortage of places to start in virtually any subsystem. What’s the best way to decide whether a hardware, software, or firmware problem is the most likely cause? Typically, hardware problems come and go, whereas software and firmware problems are consistent. Why? A hardware problem is often the result of a damaged or loose wire or connection; when the connection is closed, the component works, but when the connection opens, the component fails. On the other hand, a software or firmware problem will cause a failure under the same circumstances every time.
Another rule of thumb that’s useful is to consider the least expensive, easiest-to-replace item first. In most cases, the power or data cable connected to a subsystem is the first place to look for problems. Whether the cable is internal or external, it is almost always the least-expensive part of the subsystem, can easily come loose, and can easily be damaged. If a cable is loose, has bent pins, or has a dry, brittle, or cracked exterior, replace it.
When new software or new hardware has been introduced to the system and a problem results immediately afterward, that change is often the most likely cause of the problem.
Hardware conflicts such as IRQ, I/O port address, DMA channel, and memory address, or conflicts between the software drivers in the operating system are typical causes of failure when new hardware is introduced. New software can also cause problems with hardware, because of incompatibilities between software and hardware or because new software has replaced drivers required by the hardware.

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2012-06-29

A+: Thorough Troubleshooting *

Virtually every subsystem in the computer has hardware, software, and firmware components. A thorough troubleshooting process will take into account both the subsystem and all of its components. The following steps are involved in the troubleshooting cycle:
Step 1. Back up customer data (if possible). Before you do anything to a customer’s system, you should ensure that the system’s data has been backed up. The easiest way to ensure that you can restore the system to its “as-was” configuration is to use a disk-imaging program such as Symantec Norton Ghost or Acronis True Image. The current versions of these programs perform disk-imaging to preserve the contents of the system drive (and other specified drives) at both a data and operating system level. However, if you need to restore specified files only, the current versions of these programs also permit file-level restoration. For speed and convenience, use an external hard disk connected to a USB 2.0, FireWire, or eSATA port as the destination for the image (note that eSATA ports might not be supported by some disk-imaging programs).
Step 2. Find the most likely cause. Based on the client interview and the information from the prior post, determine the subsystem that is the most likely cause of the problem.
Step 3. Record the current configuration of the subsystem. This includes items such as the driver version, BIOS settings, cable type and length, and hardware settings. Before you change anything, record the current configuration. Depending on the item, this might include recording jumper or DIP switch settings, printing the complete report from Windows Device Manager, recording BIOS configurations, and backing up the Windows Registry. If you perform an image backup as recommended in the previous step, the Windows Registry is included as part of the backup. If you don’t record the current configuration of the system’s hardware and software before you start the troubleshooting cycle, you will not be able to reset the system to its previous condition if your first change doesn’t solve the problem.
Step 4. Change one component or setting at a time. Change a single hardware component or hardware/software/firmware setting you suspect is the cause of the problem. If you replace hardware, use a replacement that you know to be working. No matter how concerned your client is and no matter how heavy your workload, change only one component before you retest the system. Examples of changing a single component or configuration setting include swapping a data or power cable, removing the device from Windows Device Manager, changing a device’s IRQ or other hardware resource setting, reinstalling a device’s driver software, and reinstalling or repairing an application. Performing two or more of these types of tasks before you retest the system can make matters worse, and if you fix the problem you won’t know which change was the correct change to make.
Step 5. Retest after a single change and evaluate the results.
Step 6. Reconfigure or reinstall. If the problem persists, reconfigure or reinstall the device or hardware/software/firmware setting to its original condition and repeat Steps 4 and 5 with another component in the same subsystem.
Step 7. Continue until all subsystem components have been tested. Repeat Steps 4–6 until the subsystem performs normally or until you have tested all components in the subsystem. If the problem stops occurring after a change, that item is the cause of the problem. Repair, replace, or reload it as appropriate to solve the problem.
Step 8. Move on to another subsystem. If changing all components or settings in a particular subsystem does not solve the problem, move on to another subsystem that you think might be the culprit. Choose from one of the subsystems in the prior post. You will find that some problems can be deceiving; they will appear to be caused by one subsystem when in reality they are caused by another.
There are a few other techniques to consider when troubleshooting, including which components to check first, common points of failure, the fact that a device is known to be working doesn’t necessarily mean it’s new, and to keep track of your solutions.


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A+: Is a Problem Is Caused by Hardware or Software

The oldest dilemma for any computer technician is determining whether a problem is caused by hardware or software. The widespread use of Windows operating systems makes this problem even more acute than it was when MS-DOS was the predominant standard, because all hardware in a Windows system is controlled by Windows device drivers.
A troubleshooting cycle is a method that you can use to determine exactly what part of a complex system, such as a computer, is causing the problem. The troubleshooting cycle used in this section goes into more depth than the CompTIA six-step troubleshooting process. The first step is to determine the most likely source of the problem. The client interview will help you determine which subsystem is the best place to start solving the problem. In the previous example, the printing subsystem was the most likely place to start.
subsystem is the combination of components designed to do a particular task, and it can include hardware, software, and firmware components. 

For example, for the printing subsystem: 
Software: Printer driver in Windows app
Hardware: Printer, cable, parallel, serial, USB or network port
Firmware: BIOS configuration

Display subsystem software: Video drivers in Windows
Hardware: Video card (unless motherboard has integrated video), monitor, cables, port type 
Firmware: Video BIOS, BIOS configuration of video, boot priority

Audio subsystem s
oftware:  Audio drivers in Windows
Hardware: Sound card (unless motherboard has integrated audio), cables, speaker, mike, cables from CD/DVD
Firmware:  BIOS configuration for integrated audio

Mouse/pointing device subsystem s
oftware:  drivers in Windows
Hardware: Mouse or pointer device, serial or mouse port, USB port

Firmware:   BIOS port configuration, USB legacy configuration

Keyboard subsystem s
oftware:  drivers in Windows
Hardware: Keyboard, PS/2 or USB port
Firmware:   BIOS keyboard configuration, USB legacy configuration

Storage subsystem s
oftware:  drivers in Windows
Hardware: Drives, cables, power cables, drive interface card or built-in ports
Firmware:   BIOS drive configuration for PATA, SATA, USB, IEEE-1394, RAID

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2012-06-28

A+: Recording Symptoms and Error Codes

If tests rule out power and interference, proceed to tests focusing on the hardware or software that appears the most likely cause of the problem.

Which test or diagnostic routine is the best one to start with? Before you perform any specific tests, review the clues you gathered from the client. Examples of places where symptoms and error codes can be found include
Event Viewer— The System log records error information regarding drivers and system files, while the Application log records information and errors about applications within the operating system.
Device Manager— If a device in Device Manager is disabled it will be marked with a red x (Windows XP) or a down arrow (Windows Vista); if it is not configured properly there will be an exclamation point against a yellow background (Windows XP and Vista). Device Manager also displays codes in the Properties window of a device indicating particular issues.
On screen messages— Various messages can popup on the screen while a user is working in Windows. Sometimes these messages can be helpful in finding out what the problem is. If the computer fails completely, a stop error (BSOD) will be displayed offering further information as to why the system halted.
The BIOS— The BIOS can indicate errors by way of onscreen messages and beep codes. Use the particular system’s motherboard documentation to discern what these codes and messages mean.
Printer Displays— The small LCD found on many printers (especially laser printers) is used to indicate the status of the printer. From this display you can verify whether the printer is online, if there is a paper jam, identify error codes, and so on.


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2012-06-25

Defragmentation explained - hard drive si, SSD no

http://arstechnica.com/information-technology/2012/06/inside-the-ssd-revolution-mobile-devices-and-modern-oss/ is an excellent explanation of defragmentation of hard drives, and why you shouldn't do it with solid-state drives (SSDs).

2012-06-21

A+: How to Evaluate the Client’s Environment

Depending on the clues you receive in the initial interview, you should go to the client’s work area prepared to perform a variety of tests. You might need to perform several tests to rule out certain problems, and must look for three major issues when evaluating the customer’s environment, and 

    • Power issues
    • Interference sources
    • Symptoms and error codes—this might require that you try to reproduce the error


TEST...........REQUIRES
Power..........Multimeter, circuit tester
BIOS beep, error codes...List of BIOS codes, POST card/display device
Printer self-test........Printer, paper
Windows bootlog..........Start Windows w/ Bootlog option on
I/O port.......Connect loopback plugs, run 3d party diagnostcs
Video tests..........Third-party diagnostics
Hardware resources...........Windows Device Manager
Device drivers...........Windows Device Manager



Testing Power

Systems that won’t start or that have lockups or shutdowns with no error messages could be the victims of power problems. If a system malfunctions at a customer site but works properly at your test bench, power problems due to improper wiring might be to blame.

Looking for Sources of Interference

Power problems also can be caused by interference from other devices, such as copiers, vacuum cleaners, elevators, and alarm systems. If a system performs properly when moved away from its normal work area, but malfunctions when it is returned to its normal location, or if it works during the business day but not after hours (when an alarm system is activated), interference might be to blame. Power Conditioning Devicescan be effective in dealing with sources of interference.

If the problem is network-related, it might be necessary to reroute UTP (unshielded twisted-pair) cabling away from interference sources or connect the cable to a different port on the hub or switch.



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2012-06-20

A+: Client Interviews

The client interview is the all-important first step in solving any computer troubleshooting situation. During the client interview, you need to ask questions to determine the following information:
What hardware or software appears to have a problem?— The user might have an opinion about this, but don’t be unduly swayed by a statement such as “the printer’s broken”; the device or software the user believes to be at fault might simply reflect a problem coming from another source.
What other hardware or software was in use at the time of the problem?— The user probably will answer these types of questions in terms of open applications, but you will also want to look at the taskbar and system tray in Windows for other programs or routines that are running. Pressing Ctrl+Alt+Del will bring up a task list in Windows that has the most complete information about programs and subroutines in memory. To determine the exact version of a Windows-based program in use, click Help, About. View the System properties sheet to determine the version of Windows in use.
What task was the user trying to perform at the time of the problem?— Ask the questions needed to find out the specific issues involved. For example, “Printing” isn’t a sufficient answer. “Printing a five-page brochure from PageMaker to a laser printer” is better, but you’ll probably want the user to re-create the situation in an attempt to get all the information you need. Don’t forget to check the Event Viewer in Windows for details about the software running at the time of the error.  
• Is the hardware or software on the user’s machine or accessed over the network?— If the network was involved, check with the network administrator to see if the network is currently working properly. If the hardware and software are not networked, your scope for troubleshooting is simpler. 
• What were the specific symptoms of the problem?— Some users are very observant, but others might not be able to give you much help. Ask about the approximate time of the failure and about error messages, beeps, and unusual noises. 
• Can the problem be reproduced?— Reproducible problems are easier to find than those that mysteriously “heal” themselves when you show up. Because power and environmental issues at the customer’s site can cause computer problems, try to reproduce the problem at the customer’s site before you move the computer to your test bench, where conditions are different. 
• Does the problem repeat itself with a different combination of hardware and software, or does the problem go away when another combination of hardware and software is used?— For example, if the user can print from Microsoft Word but not from PageMaker, this means that the printer is working, but there might be a problem with configuration or data types used by different applications. If the user can’t print anything, there might be a general problem with the printer hardware or drivers.

Tips for Conducting the Client Interview

Sometimes, the client interview alone will reveal the answer. More often, however, you’ll need to go to the client’s work area and evaluate the hardware and software that are involved.    
During the client interview, you will make an impression on the client. Will it be “this tech knows what’s going on and wants to fix my problem” or “this tech’s a blowhard know-it all that just won’t listen!” If you want to come across as someone who’s competent and caring, and not as a blowhard who won’t listen, follow these guidelines:  
Use clear, concise, and direct statements— Clients appreciate it when you use language they can understand.
Allow the customer to complete statements— Don’t interrupt. You might think you know what they’re going to say next, but you could be wrong. If you don’t allow the customer to complete their statements, you might miss some vital information or clues about the problem.
Clarify customer statements—ask pertinent questions— Whether you think you understand what the customer said or are totally at sea, make sure you ask the questions that will help keep you on the right track. Try rephrasing what they said and ask them to agree or clarify: “If I understand you correctly, what you’re saying is....” 
• Don’t baffle the customer with technobabble— Avoid using jargon, abbreviations, and acronyms. Explain what you mean in plain language. Remember, if you can’t explain a problem or solution in everyday language, you don’t understand it either. 
• Who saw the problem? The customer!— So, listen to your customers; they may be the best way to find the solution, especially if the problem refused to show up when you’re around.

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2012-06-19

A+: Troubleshooting and a six-step process

Two factors make for successful troubleshooting: extensive computer knowledge and an understanding of human psychology. You must understand how hardware and software work to troubleshoot them. You also must treat customers with respect. By combining these two factors, you can quickly detect and solve computer problems.

To become a successful troubleshooter, you need to

    • Learn as much as possible during the client interview
    • Evaluate the client’s environment
    • Use testing and reporting software to gather information about the system
    • Form a hypothesis (a theory you will try to prove or disprove)
    • Use the troubleshooting cycle and the CompTIA six-step troubleshooting process to isolate and solve the problem, to wit:

1 Identify the problem
2 Establish a theory of probable cause (and question the obvious)
3 Test the theory to determine the cause
4 Establish a plan of action to resolve the problem and implement the solution
5 Verify full system functionality and, if applicable, implement preventative measures
6 Document findings, actions and outcomes

It is necessary to approach computer problems from a logical standpoint. To best accomplish this, PC technicians will implement a troubleshooting methodology (or maybe more than one).

As you attempt to troubleshoot computer issues, think in terms of that six-step process. Plug the problem directly into these steps.

For example, in Step 1 you might identify an issue; maybe the computer won’t turn on. For Step 2, a possible theory could be that the computer is not plugged in to the AC outlet. To test the theory in Step 3, you would plug the computer in. If it works, then great, but if it doesn’t, you would go back to Step 2 and establish a new theory. When you have reached a theory that tests positive, move on to Step 4 and establish the plan of action based on that theory, and then implement your solution. (Keep in mind that many plans of action will be more complicated than just plugging the computer in! Perhaps the AC outlet was loose, which would require a licensed electrician to fix it.) Next, in Step 5 you want to test. Always test and verify that the system is functioning correctly. If need be, implement preventative measures; for example, re-route the power cable so that it is out of the way and can’t be disconnected easily. Finally, in Step 6, you want to document your findings and the outcome. In many companies, documentation begins right when you first get a troubleshooting call (or trouble ticket), and the documentation continues throughout the entire process. You can track documentation on paper, or in an online system; it depends on your company’s procedures. Be sure to keep track of what happened, why it happened, and how you fixed the problem.

Because computer failures happen to the customer (who usually is less technically aware than you of the possible causes for the problem), you must work with the customer to create a complete list of symptoms so that you can find the right solution quickly and accurately. To do this, you need to

    • Carefully observe the customer’s environment to look for potential causes of computer problems, such as interference sources, power problems, and user error.

    • Ask the customer what (if anything) has changed recently about the computer or its environment. Anything from new hardware or software being installed, new telephone or network being installed, or even a new coffee maker or air-conditioning unit could be at the root of the problem. A simple way to ask this would be to say, “What has changed since the last time it (the PC) worked?”

    • Determine what tasks the customer was performing on the PC. You can determine this not only by asking the customer questions, but by reviewing system log files, browser history, and so on

    • Ask the customer detailed questions about the symptoms, including unusual system behavior, such as noises or beeps, office events taking place around the same time, onscreen error messages, and so on.

Because some types of computer problems aren’t easy to replicate away from the customer site, your customer might see system problems you never will, even if you attempt to reproduce the problem.


Remember, troubleshooting is the art and science of quickly and accurately determining what is wrong with a customer’s system. Troubleshooting is an art because every technician will bring his or her own experience and personality to the task. Troubleshooting is also a science because you can apply a definite method that will bring you a great degree of success.


Note: Windows generates several log files during routine use that can be useful for determining what went wrong. Many of these can be viewed through the Event Viewer. To view the contents of the Event Viewer, right-click Computer/My Computer, click Manage and click Event Viewer. The Event Viewer captures three types of information: Application errors, security audits, and system errors.

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2012-06-18

A+: Hazards

Computers and their peripherals can kill or injure you if you don’t take reasonable precautions. Here we discuss computer maintenance and the precautions you can take against these dangers.

Computer equipment and supplies can pose a number of potential hazards for the technician (and, in some cases, for computer users):

    • High voltage sources, such as computers, and peripherals, such as printers and monitors
    • Mechanical devices, such as printer mechanisms
    • Power or data cables running across floors or other locations where users could trip and fall
    • Liquids, such as those used for cleaning or refilling inkjet cartridges
    • Situational hazards, such as unsafe temporary equipment or cabling locations
    • Atmospheric hazards, such as those created by the use of toxic cleaners or the discharge of computer-room-rated fire suppression chemicals
    • Moving heavy equipment, such as laser printers, servers, large UPS systems, or print/scan/copy devices.


Computers and their peripherals can kill or injure you if you don’t take reasonable precautions. Here we discuss computer maintenance and the precautions you can take against these dangers.

Computer equipment and supplies can pose a number of potential hazards for the technician (and, in some cases, for computer users):

    • High voltage sources, such as computers, and peripherals, such as printers and monitors
    • Mechanical devices, such as printer mechanisms
    • Power or data cables running across floors or other locations where users could trip and fall
    • Liquids, such as those used for cleaning or refilling inkjet cartridges
    • Situational hazards, such as unsafe temporary equipment or cabling locations
    • Atmospheric hazards, such as those created by the use of toxic cleaners or the discharge of computer-room-rated fire suppression chemicals
    • Moving heavy equipment, such as laser printers, servers, large UPS systems, or print/scan/copy devices


High Voltage Hazards

The number-one hazard created by computer equipment is high voltage that can be present while devices are turned on and plugged in and even when some devices are unplugged and turned off. The major sources of potentially dangerous voltage include

    • Printers
    • Power supplies
    • Monitors
    • Systems in suspend or sleep modes

Printers also pose laser and mechanical hazards to technicians.

Printers

Unlike computers, printers normally do not run on safe, low-voltage DC (direct current). Although laser printers typically do use DC current, it is at a high voltage. Most impact and inkjet printers also use high-voltage AC (alternating current).

Any printer should be turned off and unplugged before being serviced. In the event of ink or toner spills, water or other liquids should not be used to clean up the mess unless the printer is turned off and disconnected, due to the risk of a potentially fatal electric shock.


The Power Supply

The exterior of practically every power supply is marked something like this:

CAUTION! Hazardous area! Severe shock hazards are present inside this case. 
Never remove the case under any circumstances.

Believe it. You can see the danger if you understand what is in the “cage” at the back of the typical power supply. Past the cooling fan it contains, you’ll see coils of heavy wire. These windings retain potentially lethal high voltage levels for a long time.

    Because any power supply you buy as a replacement is likely to have a higher wattage rating and can also have a quieter fan than your current power supply, don’t go cheap and wind up dead. Heed the warnings and replace the power supply without opening it to find out why it is broken. Make sure you purchase a UL-rated power supply.

CRT Monitors

As with the power supply, the outside of the monitor is safe. However, if you remove the cover of a CRT monitor for servicing or adjustments, you expose the danger. The high voltage anode (a metal prong covered with a red insulator, found on the wide top of the CRT) holds dangerously high voltage for days after the power is turned off.

Disassembled CRT monitors also pose the following hazards: X-rays coming from the unshielded neck of the CRT when the monitor is on, and dropping the monitor and breaking the CRT.

Replace the shielding around the neck of the CRT before using the monitor, and use padding and carefully balance CRTs and monitors during storage and transport to avoid damage.


Systems in Suspend Mode

Systems based on the ATX, BTX, or NLX standards typically go into a deep suspend mode rather than a true “off” condition when shut down by Microsoft Windows. Some ATX and BTX systems have power supplies with a separate on/off switch on the back of the unit, but some do not. For these reasons, you should disconnect the power cord from the system to avoid potentially lethal electric shock.

As with other devices, the power can be on unless you disconnect it at the source.

Precautions Against Electric Shock

This section discusses the precautions you should take to avoid the hazards covered in previous sections.

To work with electricity safely, follow these simple precautions:

    • Remove jewelry, including rings, bracelets, and necklaces. Metal jewelry provides an excellent path for current.

    • Use rubber gloves for extra insulation—rubber gloves prevent your hands from touching metal parts; however, they do not provide sufficient insulation to enable you to work on a live system.

    • Work with one hand out of the system if possible, to avoid electricity passing through your chest if your arms complete a circuit.

    • Keep your hands and the rest of your body dry; your body’s natural shock resistance drops to virtually nil when your skin is damp.

Regardless of the level of service you will provide to a component, devices such as printers, computers, monitors, and so on should be disconnected from power as well as turned off before service. This will help prevent shock hazards as well as mechanical hazards.

Do not leave the computer plugged in while you work inside it. At one time, an acceptable practice was to leave the computer plugged in but shut down and keep one hand on the power supply as a ground. This is no longer appropriate because ATX, BTX, and other modern computers aren’t really “off”; they’re in a suspend mode and power is still running through memory, expansion cards, and so on.


Discharging CRTs

Do not service CRT-based monitors as a first choice today; most companies are rapidly replacing their remaining CRTs with LCD displays to save power and desk space. You should not service any monitor unless you are a certified CRT technician. However, if you must open a CRT-based monitor for service, discharge the high voltage anode following this procedure:

    Step 1. Turn off and unplug the monitor.

    Step 2. Remove the housing carefully.

    Step 3. Attach a large alligator clip and wire from a long, flat-bladed, insulated screwdriver to the metal frame surrounding the monitor.

    Step 4. Slide the flat blade of the screwdriver under the insulator until the tip touches the metal anode clip

    Step 5. Be prepared for noise—anything from crackling to a loud pop—as the anode discharges its stored electricity. Keep the screwdriver in place for several seconds to fully discharge the anode.

    Step 6. Slide the screwdriver out without twisting it; you could damage the CRT.

This process must be repeated after each time the monitor is powered up until the housing is replaced.

Mechanical Hazards

Although computers and their peripherals are primarily electronic and electrical devices, they can pose various mechanical hazards to users, including

    • Impact and inkjet printers can pinch or crush fingers in their gears and paper feeders if the cover is removed while the printer is in operation.

    • CD and DVD trays can pinch fingers or damage cables when retracting.

• Pins in serial, parallel, VGA, and DVI cable connectors can cause puncture wounds.

    • Sharp edges on metal computer cases, card brackets, and drive rails can cause minor cuts.

To avoid mechanical hazards like these, take the following precautions:

    • Turn off printers before attempting to remove paper or label jams.

    • Follow the manufacturer’s recommended procedure for changing ink cartridges to prevent the printer from attempting to print, move the printhead, or advance paper during the process.

    • Make sure fingers, cables, and other potential obstructions are out of the way before closing CD and DVD trays.

    • Don’t touch the pins in cable connectors to avoid potential harm to yourself or ESD risks to connected equipment.

    • Handle chassis components such as computer cases, card brackets, and drive rails with care. Avoid sliding your hands along the edges of these and similar sheet-metal parts to avoid cuts and scrapes.

    • Have antibiotic ointment and appropriate bandages, including finger and knuckle bandages, handy in case of injury to hands or fingers.

Tripping Hazards

Watch out for loose cables! Whether it’s a temporary setup while you are repairing a balky PC or printer or a “permanent” office setup, power or data cables running across floors or other locations where users could trip and fall are accidents waiting to happen. When someone trips or falls because of power or data cables, both the individual and the connected equipment can be harmed.

Avoid trip/fall hazards by controlling cable sprawl. Use the following tools and techniques to manage cables:

    • Cable ties are an inexpensive way to keep overlength cables out of the way. They use Velcro or similar hook-and-loop material to provide self-adhesive properties, and come in a variety of colors you can use for color-coding or to assure that the cable tie is the same color as or a contrasting color to the cable. Cable ties are available at electronics and computer stores, as well as fabric and hobby stores.

    • To manage bundles of cables running to a particular PC or other equipment, consider cable wraps or cable trappers.

    • For temporary cable runs across floors, such as in a repair situation, a trade show, or a training class, use gaffers’ tape or duct tape to tape the cables to the floor. These types of tape leave little or no residue when used for short periods of time and can be used to hold down network, power, video, or other types of cables.

    • For long-term cable installations, use cable management systems to keep cables out of the way. These can be as simple as a floor cable concealer, which protects cables on the floor from damage, or as elaborate as cable trays, which carry cables over a suspended ceiling, or cable raceways, which conceal cable runs along wallboards or crown molding. The Cable Organizers website, www.cableorganizer.com, is a good place to start your search for permanent cable organizing solutions.

Liquid Hazards

Liquids, such as those used for cleaning computer equipment or refilling inkjet cartridges, pose a variety of hazards, including electric shock hazard when used to clean ink or toner spills in a printer, and carpet or clothing stains when refilling inkjet cartridges.

To avoid electric shock hazards caused by liquid cleaner, make sure the printer or other component is turned off and unplugged before using a liquid cleaner. To clean up spilled toner, use a toner-rated vacuum cleaner.

To avoid carpet or clothing stains when refilling inkjet printer cartridges, be sure to follow the vendor’s instructions carefully.


Situational Hazards

When you are setting up computer equipment on a temporary basis, such as for a repair or configuration before permanent installation, it might be tempting to take shortcuts that you would not consider for a permanent installation. Watch out for the following:

    • Don’t overload a worktable or bench with equipment. If the legs collapse or the tabletop gives way, both you and the equipment could be harmed. Check the rating for the furniture before piling it up with heavy printers, UPS systems, all-in-one units, 19-inch or larger CRT monitors, and similar heavyweights.

• Avoid using chairs, tables, or other surfaces as replacements for stepstools or ladders. You can fall and hurt yourself—and break equipment in the process.

    • Don’t use empty boxes as temporary stands for equipment. If you must use boxes until the furniture arrives, use boxes that still contain equipment—and don’t put heavy components atop lightweight boxes.

    • Watch out for trip/fall hazards from power and data cables, surge suppressors, and the like. See “Tripping Hazards,” earlier in this chapter, for methods to avoid tripping hazards during short-term computer setups.

Situational hazards can also pose potential threats during permanent computer or peripheral installation:

    • Don’t overload tempered-glass desktops or other furniture. These items usually have clearly-marked load limits. Exceed them, and watch the monitors or printers crack the glass as they fall.

    • Tag power and data cables to make it easy to tell which cables go with what equipment.

Atmospheric Hazards

The major atmospheric hazard for computer users is the use of Halon in the fire-extinguisher systems of computer rooms. Halon is toxic to humans (it can cause cardiac problems), although it is safe for computer equipment. If you work in a computer room or other area that uses Halon-based fire extinguishers or sprinkler systems, make sure you do not breathe in Halon fumes. Exit the area immediately in case of fire.

DuPont FE-36 is a safe alternative to Halon, providing comparable fire suppressant control for Class A, B, and C fires, while being far less toxic. To learn more about FE-36, see the DuPont FE-36 information page at http://www2.dupont.com/FE/en_US/products/fe36.html.

Heavy Equipment Hazards

Laser printers, workgroup-grade all-in-one units, high-capacity UPS battery backup systems, and servers are potential hazards because of their weight and bulk. Take the following precautions to avoid injury and damage

    • Move equipment in its original cartons and packaging whenever possible.
    • Use wheeled freight dollies or carts to move equipment.
    • Use “team lift” methods to move heavy and bulky items.
    • Wear a back brace.


Environmental and Accident Incident Handling

Even with the best of precautions, environmental issues and accidents involving computers and related technologies can and do happen. Use the following procedures to handle problems safely and professionally

    • Know who to contact in case of injuries to personnel, damage to equipment, fires, or chemical spills.

    • Know how to reach an outside phone line to call 911 in case of serious emergency.

    • Review and follow procedures for cleaning up chemical spills, retrieving damaged computer equipment, or other problems.

    • Have MSDS information available for computer-related supplies and chemicals.

    • Write up the incident in a professional manner, noting time, place, personnel involved, and other important information.

    • Work with other personnel to solve problems resulting from the incident.

    • Learn from the incident to help avoid future problems.


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2012-06-17

A+: More ESD Precautions

Caution!: All work mats and wrist straps should have a 1-megohm resistor, to stop any high voltage that comes through the ground line from injuring you!

Correct equipment storage should have two goals: Eliminating the possibility of ESD, and protecting equipment from impact damage.

To protect equipment from ESD, store equipment in the Faraday cage antistatic bags originally supplied with the equipment; retain bags for installed equipment for reuse. Faraday cage antistatic bags feature a thin metallic layer on the outside of the bag, which is conductive and prevents ESD from penetrating to the components inside. Thus, metalized metallic bags should never be used for temporary mats for components; if you lay a component on the outside of the bag, you’re laying it onto a conductive surface. Colored antistatic bubble wraps also work well for parts storage and can also be used as a temporary mat, too. If you use bubble wrap, make sure it is antistatic.

Store components in appropriate boxes to avoid physical damage. If the original boxes have been discarded, use cardboard boxes that have enough room for the component, the Faraday cage bag around the component, and antistatic padding.


A grounded wrist strap can help prevent ESD, but you should also follow these additional precautions:

• If you must handle expansion cards and other devices with chips without suitable antistatic protection, never touch the chips! Most current products use a CMOS (Complementary Metal-Oxide Semiconductor) design, which has practically no resistance to ESD; as little as 30V of ESD can damage CMOS-based devices.

    • Hold expansion cards by the brackets, never by the gold edge connectors, chips, or circuitry.

    • Wear natural fibers, such as cotton and leather-soled shoes, instead of rubber or synthetics, to avoid ESD buildup.

    • Use an antistatic spray (commercial or antistatic fabric softener/water mixture) to treat carpeting to reduce ESD.

    • Use antistatic cleaning wipes on keyboards, monitors, and computer cases to reduce static buildup. Turn off the power, and if you use a liquid cleaner, always spray the cloth, never the device!



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2012-06-16

A+: Protect Yourself!

You can best equalize the electrical potential of a computer or component that is being serviced by placing the computer or component on an antistatic work mat equipped with a wrist strap; attach your wrist strap to the mat. This will help place you and the component at the same level of electrical potential, and thus eliminate the “need” for ESD to occur to equalize the potential.


Caution: You should use a commercial wrist strap for most types of computer service, but there is one major exception: Never ground yourself when you are working with high-current devices, such as when you discharge a CRT monitor. Grounding yourself to such devices could cause your body to receive a fatal high-current electrical charge.

For additional safety, use the alligator clip on the antistatic mat to attach to the component or computer you are working on. Attach the clip to unpainted metal on the chassis, such as the frame. This provides superior equalization for the mat, you, and the hardware on the mat.

Table mats connected to a grounded power supply are useful tools for preventing ESD on working computers, especially if users are reminded to touch the mat or grounded keyboard strip first. Antistatic cleaning spray and antistatic carpet spray should be used in any carpeted office to reduce static, especially in the winter when dry heat causes buildup.

Caution: Do not leave the computer plugged in while you work. This does not minimize the chances of ESD, and you could damage equipment if you attach or remove it. This is because virtually all modern computer systems still draw power even when they have been shut down.

Both wrist straps and the work mats include alligator clips that are attached to the system chassis to equalize electrical potential between the wearer and the computer. Wrist straps use hook and loop or other types of adjustable closures; it’s important to wear the wrist strap comfortably snug so that the metal plate underneath the resistor touches the skin to provide proper conductivity.

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2012-06-15

A+: Safety - MSDS (Material Safety Data Sheet) and ESD (Electronstatic Discharge)

What happens if a toddler decides to taste the ink in a printer cartridge? The Material Safety Data Sheet (MSDS) knows. Many consumable products such as cleaners and printer cartridges have an MSDS. In more and more cases today, this information is available from the manufacturer’s website on the Internet.
The MSDS can be used to
• Determine safe storage practice
• Determine treatment if the product is accidentally swallowed or contacts the skin
• Determine safe disposal methods
• Determine how to deal with spills, fire, and other hazards


Anyone who works with electronics, especially disassembled components, needs to be very concerned about ESD. ESD is the static electricity discharge that happens when two differently charged objects (such as your body and a computer component) come in contact with each other. ESD is an invisible killer of memory modules, interface cards, hard disks, and other computer components, because ESD buildup and discharge happens long before you actually notice it.

You might dread shaking hands with a new acquaintance in the winter because you’ll get a shock, but ESD discharges far below the 3,000V level that you can actually feel can still destroy chips. As little as 30V of ESD is enough to destroy the current generation of low-powered chips, and you can build up as much as 20,000V of ESD from walking across a carpeted room in the winter if you shuffle along.

ESD damage is “invisible” for another reason: It leaves in its wake equipment that has no visible damage but simply won’t work reliably.


ESD damage is a major cause of intermittent failures, which are the bane of computer technicians everywhere. An intermittent failure is the classic “it wasn’t working when I called you” kind of problem that “goes away” when you examine the system but recurs from time to time later. 

You can prevent ESD by taking proper precautions when you install or remove components, store and transport components and/or use computers & devices. 

Unequal electrical potential between you and the device on which you’re working is the major cause of ESD. When your body has a higher electric potential than the device or component with which you’re working, an ESD from your body to the device or component equalizes the potential—but at the cost of damage or destruction to the component.

Although the greatest danger of ESD occurs when you have the system open and are working with components, PC users can also cause ESD problems when working with closed systems.

One way to prevent ESD is to equalize the electric potential of your body and the components on which you’re working.

Specific items enable you to perform electrical testing on power entering the system (AC) and power levels inside the system (DC), prevent ESD damage to components, and prevent electrical shock caused by worn insulation on power cables, such as:

    • AC/DC multimeter with Ohm and Continuity options— Tests power inside the system and at wall outlets

    • Grounded AC circuit tester— Fast testing for wall outlets; many offices and homes are incorrectly wired, and the tester will help you determine whether this is the problem

    • Antistatic mat and wrist strap— Prevents ESD, which can damage parts and systems

    • Electrical tape— Temporarily repairs worn spots in the insulation of AC and DC power cables until replacements can be obtained

    • Battery tester— Helps determine the condition of batteries used in motherboards and other components


 
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2012-06-14

A+: Disposal of Obsolete Hardware

If you send your obsolete PC, printer, or monitor to a landfill, it will have plenty of company. Millions of old units go there every year; it’s legal (except for monitors which contain lead or mercury), but it’s also a waste of equipment that could teach somebody something or still be useful to someone. Here are some better ways to deal with obsolete computers and peripherals:
• If possible, try to dispose of your working, cast-off computer equipment by giving it to a school, charity or especially a computer rebuilding society such as Freegeek.org. These organizations might be able to wring additional years of useful life out of the equipment and are usually grateful for the opportunity.
• To dispose of non-working equipment, see if an electronics trade school is willing to take the equipment for classroom use. Some electronic and computer service facilities will allow you to drop off defective monitors with payment of a small disposal fee.
• Use “computer” and “recycling” in a major search engine to find options for constructive disposal of both working and non-working equipment.

Hard disk drives in castoff machines can be a treasure trove of confidential information for the recipients, even if you format or repartition the drives. Many open souce freeware data recovery programs such as Norton Unerase, Norton Unformat, Ontrack Easy Data Recovery, and others can pull all kinds of information from an intact hard disk, including credit-card, bank, and proprietary company data.

Open source hard disk erasure programs such as dBan and other programs that overwrite data areas of the drive repeatedly are designed to help prevent easy data recovery. However, forensic data-recovery tools intended for use by law-enforcement organizations can be purchased and used by anyone to retrieve data, even if it has been overwritten.

For maximum security for your personal or company data, if you do not have a binding agreement with a rebuilding society for them to erase the data, take the hard disks out of any machine you’re disposing of and physically destroy them. Open the cover of each hard disk drive and destroy the platters with a hammer.

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2012-06-13

A+: Recycling Batteries, Solvent and Toner

Nothing lasts forever in the computer business. Whether it is a worn out real-time clock battery, an obsolete monitor, or an empty toner cartridge, there’s a right way to get rid of it or to recycle it. Generally, the more “durable” a computer-related item is, the more likely it is that it should be recycled when it reaches the end of its useful life, instead of simply being discarded.

Recycling is important and can have legal ramifications for a company. In this section you learn the proper way to recycle toner cartridges and batteries and how to dispose of chemical solvents, monitors, and other computer hardware. When dealing with computers, power, networking, and anything else in IT, remember to put safety on the top of your priority list. Computer equipment is not a toy and should be treated with care. Another issue to consider is how you dispose of your technology, since this will affect the environment. Most companies have procedures in place that specify what to do with computers, monitors, batteries, and other technology equipment after it has outlived its usefulness to the company.

Batteries no longer contain significant amounts of mercury, a highly toxic chemical that can cause memory loss, vision impairment, and other health issues in high exposures, but today’s batteries still contain chemicals that should not go into landfills.

Depending on the type of battery that you have replaced, you might find more than one option for disposal of the old ones:

    • Some stores have drop-off bins for watch and calculator batteries; the popular 3.0V lithium CR-2032 or equivalent battery used on motherboards to maintain the CMOS and RTC settings could be disposed of this way.

    • Hardware stores and home centers often feature drop-off bins for Ni-Cd, NiMH, or Li-ion rechargeable batteries, such as those found in computer, PDA, or cell phone power supplies or power tools.

    • To recycle alkaline or other types of dry or wet-cell batteries, including batteries used in UPS battery backup systems (which often contain lead), as well as rechargeable, watch, and calculator batteries, contact companies that specialize in safe battery disposal or recycling. To locate companies, check your local telephone directory or perform a web search using search terms such as “battery recycling.”


Toner cartidges and containers can contain toxics, and many manufacturers of laser toner and inkjet printer cartridges want you to recycle the empty cartridges; these companies provide postage-paid envelopes or mailing labels to help you return the empty product.

Otherwise, contact local rebuilders of laser toner or inkjet cartridges. Some of these companies might pay you a small fee per empty toner cartridge for popular printer models or might offer other inducements.



When you’ve used the contents of a cleaning product container, check the label for container-disposal instructions. Depending on the product, you might
• Be able to recycle the plastic container in household recycling; this is most often true for citrus-based and other mild cleaners
• Be required to follow toxic material disposal procedures; check with your local EPA office for a “Tox-Away Day” and store your empty containers for safe disposal at that time
If you need additional information about disposing of a particular type of container, check the product’s material safety data sheet or MSDS.

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2012-06-12

A+: Network and Internet Troubleshooting

Can’t Access Network Resources

 
If an error message such as Duplicate Computer Name or Duplicate IP Address is displayed during system startup, open the Network icon and change the name of the computer or the system’s IP address. Contact the network administrator for the correct name or IP address settings to use.

Significant Drops in Network Performance

 
Significant drops in network performance can be traced to a variety of causes, including
• Damage to cables, connectors, hubs, and switches
• Expanding network capacity with hubs in place of switches
• Connecting high-speed NICs to low-speed hubs or switches
• RFI/EMI Interference with Wireless Networks
If network usage patterns remain constant but some users report lower performance, check cables, connectors, and other network hardware for physical damage. Dry, brittle, and cracked cables and connectors can generate interference, which forces network stations to retransmit data because it wasn’t received correctly. Replace damaged cables and connectors.

Use diagnostic programs supplied with the network adapter if the same brand and model of adapter is used by multiple computers. These diagnostics programs send and receive data and provide reports of problems.

If all the users connected to a single hub or switch report slowdowns, check the hub or switch. Replace a hub with a switch to see an immediate boost in performance. Continue to use switches to add capacity.
Make sure that computers with Fast Ethernet (10/100) hardware are connected to dual-speed hubs or switches to get the benefits of 100 Mbps performance. 10/100 cards will run at 10 Mbps if connected to 10Mbps hubs or switches. Enable full-duplex mode if the cards and hubs or switches support it to boost performance to 20 Mbps (with 10BASE-T) or 200 Mbps (with 10/100 cards running Fast Ethernet).
Make sure that computers with Gigabit Ethernet (10/100/1000) hardware are connected to Gigabit Ethernet switches to get the benefits of 1000 Mbps performance.

Radio frequency interference (RFI) is closely related to EMI, and RFI/EMI interference can have a big impact on wireless network (WLAN) performance. For the A+ exam, some things to consider include cordless phone and microwave usage. Because these devices can also inhabit the 2.4 GHz frequency range used by 802.11b, g, and n networks, they can interfere with the network signal. Because 2.4GHz cordless phones use spread-spectrum technology to help avoid eavesdropping, it is not possible to configure these phones to use a particular 2.4GHz channel.

To help avoid interference from other wireless networks, configure your 2.4GHz wireless network to use one of the non-overlapping channels ((1, 6, or 11). Some anecdotal evidence suggests that channel 11 is less likely to receive RFI from 2.4GHz cordless phones.

You should also consider using cordless phones that use frequencies that will not interfere with 2.4GHz or 5GHz wireless networks, such as phones using DECT (1.9GHz) or DECT 6.0 (6.0GHz) frequency bands.

Unattended PC Drops Its Network Connection

Incorrect settings for power management can cause stations to lose their network connections when power management features, such as standby mode, are activated. Check the properties for the network adapter to see if the adapter can be set to wake up the computer when network activity is detected.

All Users Lose Network Connection

 
If the network uses a bus topology, a failure of any station on the network or of termination at either end of the network will cause the entire network to fail. Check the terminators first, and then the T-connectors and cables between computers. If you suspect that a particular computer is the cause of the failure, move the terminator to the computer preceding it in the bus topology. Repeat as needed to isolate the problem. Replace cables, connectors, or network cards as needed to solve the problem.

If the network uses a star topology, check the power supply going to the hub, switch, or wireless access point, or replace the device.

If only the users connected to a new hub or switch that is connected to an existing hub or switch lose their network connection, check the connection between the existing hub or switch and the new one. Most hubs and switches have an uplink port that is used to connect an additional hub or switch. You can either use the uplink port or the regular port next to the uplink port, but not both. Connect the computer using the port next to the uplink port to another port to make the uplink port available for connecting the new hub or switch.

If the uplink port appears to be connected properly, check the cable. Uplink ports perform the crossover for the user, enabling you to use an ordinary network cable to add a hub or switch.

If you use a crossover cable, you must connect the new hub or switch through a regular port, not the uplink port.

Users Can Access Some Shared Resources But Not Others

Users who need to access shared resources on a network using user/group permissions must be granted permission to access resources; different users are typically allowed different access levels to network resources. Contact the network or system administrator for help if a user is prevented from using a resource; the administrator of the network or peer server will need to permit or deny access to the user.

Can’t Print to a Network Printer

Problems with network printing can also come from incorrect print queue settings and incorrect printer drivers.

When you configure a network printer connection, you must correctly specify the UNC path to the printer. For example, if the printer is shared as LaserJ on the server Xeon3, the correct UNC path to specify in the printer properties sheet would be
\\Xeon3\LaserJ

If a shared printer connected to a Windows system is available at some times, but not at other times, open the printer’s properties sheet and adjust the Scheduling Option setting.

Ping and Tracert Work, But User Can’t Display Web Pages with Browser

If Ping and Tracert receive output from the specified websites but the web browser cannot display web pages on those or other sites, the browser configuration might be incorrect.
If the browser doesn’t use the correct configuration for the connection type, no pages will be displayed. With dial-up Internet connections, either the user must manually open the connection or the browser should be set to dial the connection. If a proxy server or special network configuration is needed, this must be configured in the browser. 


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2012-06-11

A+: Network Command-Line Tools

Windows contains several command-line tools for troubleshooting and configuring the network. These include the following:

    • Net— Displays and uses network resources
    • Ping— Tests TCP/IP and Internet connections
    • Tracert— Traces the route between a specified website or IP address and your PC
    • NSLookup— Displays detailed information about DNS
    • IPConfig— Displays detailed TCP/IP configuration about your Windows NT/2000/XP system

Using the Net Command

Windows includes the Net command for use in displaying and using network resources from the command line. Some of the Net commands you can use include

    • Net Help—Displays help for a Net option; for example, use Net Help View for help with the Net View command.

    • Net Use—Maps a network drive to a shared resource on the network; for example, Net Use Q: \\Tiger1\shared. In this example, Q: will behave just like any other drive letter such as C:, D:, and so on. The only difference is that it will redirect to another computer on the network.

    • Net View—Displays other hosts on the network.

    • Net Helpmsg errorcode#—Displays the meaning of any Microsoft error code.

To display a complete list of Net commands, type Net /? |More from the command prompt.

Using Ping

Windows can use the Ping command to test TCP/IP, check for connectivity to other hosts on the network, and check the Internet connection for proper operation. Ping is a more reliable way to check an Internet connection than opening your browser, because a misconfigured browser could cause you to think that your TCP/IP configuration is incorrect.

To use Ping to check connectivity with another host on the network, follow this procedure:

    A. Open a command-prompt window.

    B. Type Ping IP address or Ping servername in order to ping another host on the network, then press Enter. For example, to ping a router, typical syntax would be Ping 192.168.1.1.

To use Ping to check your Internet connection, follow this procedure:

    A. Start your Internet connection. If you use a LAN to connect to the Internet, you might have an always-on connection.

    B. Open a command-prompt window.

    C. Type Ping IP address or Ping servername and press Enter. For example, to ping a web server called www.erewhon.net, type Ping www.erewhon.net  .

By default, Ping sends four data packets from your computer to any IP address or servername you specify. If your TCP/IP connection is working properly, you should see a reply from each ping you sent out indicating how quickly the signals traveled back from the target and the IP address or URL of the target. The replies indicate that the host is alive. Any other message would indicate a problem, for example the “Request timed out” or “Destination host unreachable” messages would require further troubleshooting. Keep in mind that if it’s the local computer that is configured incorrectly, you might not be able to “ping” anything! Also watch for the amount of time the ping took to reply back. A longer latency time could indicate network congestion. Conversely, the lower the time in milliseconds (ms), the faster your connection. Connection speeds vary a great deal due to various factors, such as Internet network congestion, server speed, and the number of relays needed to transfer your request from your computer to the specified server. To check relay information, use the Tracert command.

Using Tracert

The Tracert command is used by Windows to trace the route taken by data traveling from your computer to an IP address or website you specify. By default, Tracert will check up to 30 hops between your computer and the specified website or IP address. To use Tracert to check the routing, follow this procedure:

    A. Start your Internet connection. If you use a LAN to connect to the Internet, you might have an always-on connection.

    B. Open a command-prompt window.

    C. Type Tracert IP address or Tracert servername and press Enter. For example, to trace the route to a Web server called www.erewhon.tv, type Tracert www.erewhon.tv. Tracert displays the IP addresses and URLs of each server used to relay the information to the specified location, as well as the time required.

To see help for the Tracert command, type Tracert without any options and press the Enter key.

Using NSLookup

NSLookup is a command-line tool used to determine information about the DNS. When NSLookup is run without options, it displays the name and IP address of the default DNS server before displaying a DNS prompt. Enter the name of a website or server to determine its IP address; enter the IP address of a website or server to determine its name. Enter a question mark (?) at the prompt to see more options; type exit, and then press Enter to exit the program.

Using Ipconfig

If you’re having problems seeing other computers on the network or connecting to the Internet on a network that uses server-assigned IP addresses, type IPConfig /release and press Enter; and then type IPConfig /renew and press Enter to obtain a new IP address from the DHCP server on your network.

The IPConfig command-line utility is used to display the computer’s current IP address, subnet mask, and default gateway. Ipconfig combined with the /all switch will show more information including the DNS server address and MAC address, which is the hexadecimal address that is burned into the ROM of the network adapter.

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2012-06-10

A+: Browsing and Security

You can configure Internet Explorer’s default security settings for Java, ActiveX, and other potentially harmful content through the Internet Options’ Security tab. Open the Internet Options tab with Control Panel, or click Tools, Settings, Internet Options within Internet Explorer.

Depending on the version of Internet Explorer there will be five or four default security settings: High, Medium-high, Medium, Medium-Low, and Low. High blocks almost all active content and prevents websites from setting cookies (small text files that can track website usage). Medium (the default) enables some active content but blocks unsigned ActiveX controls. Medium-low blocks unsafe content but downloads other content without prompts, and low has no safeguards.

Each setting is matched to a web content zone. By default, all sites not in other zones are placed in the Internet zone, which uses Medium-high security (Medium on older versions of Internet Explorer). The local Intranet zone uses Medium-low security by default (medium in older versions). Trusted sites use Medium security by default (Low in older versions); restricted sites use High security by default.

To add or remove sites on the local Intranet, Trusted, or Restricted site list, select the zone and click Sites.

By default, local Intranet sites include all local sites, all sites that don’t use a proxy server, and all UNC network paths. Remove check marks to restrict these options. Click Advanced to add or remove a specific site or to require a secured server. Trusted or Restricted sites display the Add/Remove dialog box immediately.

Click Custom from the main Security tab to adjust the default settings for any security level. If the settings of any zone are misconfigured, one can return to default settings for an individual zone or reset security of all zones by clicking the Reset All Zones to Default Level button.

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2012-06-09

A+: Browser and Script Setup *

A web browser, such as Microsoft Internet Explorer or Mozilla Firefox, is the main interface through which you navigate the Internet. Internet Explorer is a standard component of Windows. Updates and newer versions can be downloaded manually from the Microsoft website or via Windows Update. Other browsers can be downloaded in compressed form and installed manually.
Depending on how you connect with the Internet, you might need to adjust the browser configuration.
Typical options you might need to change include
Proxies for use with LAN-based or filtered access— Users who access the Internet through a local area network might be doing so through a proxy server. A proxy server receives a copy of the website or content the user wants to look at and checks it for viruses or unapproved content before passing it on. The proxy server information is set through the browser’s configuration menu (for example, Internet Options in Internet Explorer).
Automatic dial up for convenience— Internet Explorer and most other browsers can also be set to dial up the Internet automatically whenever you start the browser to make Internet access easier. This option is very useful for dial-up connections.
Email configuration— Most browsers include an email client; the settings for the email server and other options must be made to allow email to be seen and replied to within the browser.
Disable graphics— Users with extremely slow connections who view primarily text-based pages can disable graphics for extra speed.
Security settings for Java— Advanced features, such as Java and ActiveX, make sites more interactive, but might also pose a security risk; these features can be limited or disabled through the Security menu.
You can also adjust default colors and fonts and the default start page.

Generally, you should use all the features possible of the browser unless you have speed or security concerns that lead you to disable some features.

Setting Up Your Browser to Use Your Internet Connection



In most cases, users will want the Internet to be available as soon as they open their web browser. Because some users have dial-up connections and some networks use proxy servers to provide firewall protection or content filtering, you might need to adjust the browser configuration to permit Internet access.
To view or adjust the browser configuration for Internet Explorer, follow this procedure:
A. Open Internet Explorer.
B. Click Tools, Internet Options.
C. Click the Connections tab.
D. If the Internet connection uses a dial-up modem, select the correct dial-up connection from those listed and choose Always Dial (to start the connection when the browser is opened) or Dial Whenever a Network Connection Is Not Present. Click Set Default to make the selected connection the default.
E. If the Internet connection uses a network, click Never Dial a Connection, and click LAN Settings to check network configuration.
F. Ask the network administrator if you should use Automatically Detect Settings or whether you should specify a particular automatic configuration script.
G. Click OK to save changes at each menu level until you return to the browser display.
If a proxy server is used for Internet access, it must be specified by servername and port number.
A. From the Connections tab, click LAN settings.
B. From the Local Area Network (LAN) Settings window, you have two options underneath Proxy Server. If a single proxy server address and port number is used for all types of traffic, click the Use a Proxy Server checkbox and enter the address and port number. However, if different proxy servers or ports will be used, click the Use a Proxy Server checkbox and click the Advanced button.
C. Specify the correct server and port number to use.
D. Click OK to save changes at each menu level until you return to the browser display.

Enabling/Disabling Script Settings

Some networks use a separate configuration or logon script for Internet access. To specify a script with Internet Explorer, click Tools, Internet Options, Connections, LAN Settings, Use Automatic Configuration Script. Enter the URL or filename of the script and click OK.
You can also configure Internet Explorer to automatically detect the settings if your network is configured to provide them. However, if you enable this option and the network is not configured to provide them, Internet Explorer will not be able to connect to the Internet. 

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