So, you have a computer with a problem. Where do you start? Sometimes, that answer is obvious. If you have a machine that won't power on, the first thing to check is if the power is connected. Then, check the power supply. Is the voltage switch set correctly? Is the power supply on-off switch in the on position? If the answer to these is yes, the next thing to do is try a known good power supply. If that works, you have found the problem. Occasionally, that won't work either, but then you have reason to suspect a bad motherboard; there aren't too many other possibilities.

More often, however, the source of the problem won't be so obvious, or it will seem obvious, but nothing you try works. While experience helps more than anything else, there are certain principles and concepts that ease the job of diagnosing a computer.

All Might Not Be What It Seems

All might not be what it seems. The best example is when the computer locks up, as discussed in tutorial 9, "Input Devices." Many people see that the pointer freezes and assume that their mouse just broke. They buy a new mouse, and unless the computer locks up immediately, they think the the problem is solved. Here's what happened to me on two laptops. The machines wouldn't go into standby or hibernation, and attached printers stopped printing. In every case, the error messages blamed the problem on the driver of an item that was working normally: in one case, it was the keyboard driver; in another, a COM port driver; in the third, a network adapter driver. The problem, however, had nothing to do with these drivers. In fact, keyboard and COM port drivers rarely, if ever, exhibit any problems. The problem in each case turned out to be the recent installation of a USB device; a scanner, a Web cam, and a hard drive. Even with the device disconnected, the mere presence of one of these drivers in the system caused these problems. Uninstalling the drivers, and in the case of the Web cam, removing every vestige of the software, solved the problem. The oddest thing is that all three of the USB devices worked perfectly.

So, to repeat the question, how do you know where to start? For those who work in technical support for certain notorious hardware and software companies, the answer is anywhere but with their product. However, if you're trying to find the real reason, the first thing you'll have to accept is that a given problem could be caused by almost any component in a system. Therefore, the troubleshooting procedure should start with the most likely culprit and then proceed to the next most likely once the most likely has been ruled out. If nothing is obvious, there are other ways to find the problem, which we discuss throughout this tutorial.

Note There comes a point at which it is not worthwhile to diagnose a problem, such as when you'll be spending more time and/or money than the computer is worth, or when it would be easier to simply back up the data, if desired, format the hard drive, reinstall the OS and programs, and restore the data.

Basic Troubleshooting Rules

There are basic rules to follow when troubleshooting:

Make only one change at a time: If you make more than one change at a time, you won't know which change solved the problem. If a change you made didn't help, undo the change before trying the next one.

Record all changes: It can be very difficult to remember all the changes you've made, especially if you've tried several. There's no sense in repeating changes; and if you haven't solved the problem and need to turn the machine over to another technician, the machine should be the same as when you got it.

Keep a record of all error messages: We discuss error messages later in this tutorial.

Seek assistance: Others might have experience with the problem you are having. Ask colleagues. Look on the manufacturer's or developer's Web site for their knowledge base or frequently asked questions (FAQs), or call the company. In many cases, there is a simple fix or software patch to solve your problem. You can also search the Internet for the problem; in many cases, there are forums where people post problems and others give recommended solutions. You can find tips on obtaining tech support later in this tutorial.

On the CD See the Industry Contacts document on the accompanying CD-ROM for a list of helpful Web sites.

Questions to Ask

There are a series of questions to ask when you begin to troubleshoot a problem:

Is there an error message or beep code? We discuss error messages and beep codes later in this tutorial.

Had the computer been physically moved just before the problem started? When a computer is moved, cables often become disconnected, including the power cord. If the computer has been moved from one place to another and the case sustains enough shock, internal components can become partially or fully dislodged.

Were any changes made to the computer just before the problem surfaced? These changes include configuration changes, or installation or uninstallation of hardware or software.

Diagnostic Tools

Thankfully, trial and error isn't the only way to diagnose a problem. Many hardware- and software-based tools exist to let you know what is wrong. Many of these were discussed in previous tutorials. A few others are described here:

CheckIt (smithmicro.com/checkit): There is a series of programs designed to help you diagnose and fix PC problems. The most relevant title is CheckIt Professional, which has a battery of tests for just about every aspect of the computer. Additionally, it has professional features such as the capability of running from a bootable floppy. This is similar to Micro 2000's Micro-Scope. CheckIt offers a POST card as well.

AMI Diag (ami.com): This is very similar to CheckIt Professional.

Diagnostic Utilities from Hardware Manufacturers: Many computers come with their own diagnostic utilities. For example, HPDiag comes with Hewlett-Packard computers and some other HP products.

Norton SystemWorks (norton.com or symantec.com): This is a set of programs including Norton Anti-Virus and Norton Utilities. Norton Utilities has a set of tools that can be used to solve hard drive and other problems. It is a useful program, but one of its main features, the capability of running in the background to prevent problems, can be troublesome. There was a case in which a user found that he had only 3GB of space left just one day after having 24GB left, but Windows showed no evidence of additional files. It turned out that a program he ran was creating and deleting 1GB temporary files, and a feature of Norton Utilities, Delete Protect, was rescuing these temporary files from deletion. The user finally found the files in the Norton Recycle Bin. In fact, if you encounter a computer with an inexplicably small amount of remaining hard drive space, and the computer is running Norton Utilities, check the Norton Recycle Bin. Of course, the anti-virus program is particularly important (see tutorial 2, "System Configuration and Computer Hygiene," for more information on viruses). Norton and others even have a program that can "unformat," possibly saving data from a drive that has been formatted.

McAfee Clinic (mcafee.com): In addition to the highly recommended Virus-Scan Online (that works on all versions of Windows), McAfee Clinic has several programs, all online only, that can solve computer problems. Unfortunately, most of these programs run only on Windows 9x and not on 2000 or XP. The most helpful programs in the set are FirstAidOnline, which includes a registry cleaner and some other assorted utilities, and UninstallerOnline, which includes a very helpful utility called QuickClean, which deletes unnecessary files. While these are very helpful for Windows 9x, many other programs available perform similar functions and do work on all versions.

McAfee has many programs available to download or purchase that can be installed on a system to diagnose and repair many problems with Windows.

Registry cleaners: There are many other registry-cleaning utilities available, most of which work with all versions of Windows. A notable one is RegCleaner, available free from jv16.org.

Information-Gathering Utilities

There are also utilities designed simply to obtain information from your computer. This information includes installed hardware and software and even some software registration codes. Again, some of these were discussed in previous tutorials:

System Information: Available from Start > Programs (or All Programs) > Accessories > System Tools, this applet provides a comprehensive report of many aspects of the computer.

Belarc Advisor: Belarc is a great program that can be used to get a wealth of very useful information from a computer. Download free from belarc.com, but note that Belarc's license allows personal use of Belarc Advisor only; it is not licensed for any commercial purpose. Therefore, use it only on your own personal computers.

McAfee and Norton: McAfee FirstAidOnline and Norton SystemWorks have information-gathering programs.

Two Excellent Diagnostic Programs

PC Certify (pccertify.com) and the Micro-Scope diagnostic program by Micro 2000 (micro2000.com) are useful in many ways. They operate by using their own proprietary OSs that bypass DOS and Windows problems. Their OSs read the system hardware and report a complete list of information that can help to diagnose the PC. They can also run hundreds of tests on components such as memory, video, hard drives, floppy drives, and CD drives. They will also help to determine if you have hardware conflicts, and will allow you to see which IRQs are being used and which are available so you can get things straightened out. They also can be used to perform a low-level format and a secure wipe (complete erasure) of a hard drive. They are useful in running burn-in tests and creating a report of the results. A burn-in test is a series of individual tests run over a course of several hours for the purpose of certifying a newly built computer.

POST cards are available from each company. They are used when a system will no longer boot up or run the diagnostic software. They will help in determining the cause of a dead system and can tell you whether the problem lies in memory, processor, a PCI or ISA slot, video system, and so forth. They come with guidetutorials filled with POST codes for most BIOSs. The guidetutorials list the meaning of each code and provide recommended solutions. They are big time savers and can eliminate many hours that would be spent swapping components.

Many other companies make products designed to perform the same functions. They range in price and vary from slight to great in their abilities to diagnose different problems.

The biggest advantage to this type of software and a POST card is that you can rule out or correct hardware issues before you try to deal with software issues. For example, if you are installing a new component and are having trouble with it, you can first see if the component is defective. You can then see if it needs to have jumpers changed, if applicable. Afterward, you can go ahead and troubleshoot the software and driver issues. You can see that this process will save you lots of time rather than installing and uninstalling drivers and software over and over again when the problem was hardware all along.

Tip It is a good idea if you do this type of work on a regular basis to have tools like this available so you can get the problems diagnosed quickly and cost-effectively. If you are just an occasional hobbyist, then you might find that swapping components and trial and error are just fine for you.

Obtaining Assistance

As covered elsewhere in this tutorial, obtaining assistance is crucial to effective and timely repair. There are two categories of assistance sources: manufacturers and information sharing groups.

Manufacturers

This includes hardware manufacturers, software developers, ISPs, and any organization that provides a product or service that you are troubleshooting. Help can be available in any form, including telephone support, live chat, e-mail, Usenet newsgroups, Web page form submission that leads to various types of responses, and others. Manufacturers prefer that their customers use self-service help such as FAQ pages and knowledge base searches, and often, this provides the information you need. A knowledge base is a collection of articles providing all information made available by a manufacturer. Many businesses force you to try self-service support before they supply contact information. This is usually reasonable, because some people will ask questions the answers to which are easily found in the product's documentation. With some other companies, however, important information is nowhere to be found; self-service support pages contain nothing but a rehash of the product's inadequate help files; and even if you can locate contact information, getting personalized support is about as easy as having your teeth pulled. Some other companies are easy to contact but often provide useless or incorrect information, and still others give you the runaround either because of incompetence or because they apparently hope you'll just go away. Fortunately, there are enough businesses that make good quality products and provide good or excellent support, that there is usually no need to buy from the bad ones.

Tip When visiting a Web page, you'll almost always find assistance under the "Support" heading.

Some support is free of charge, especially under warranty, but some requires payment. Charges can be prohibitive. For example, one company charges $25 to troubleshoot an out-of-warranty inkjet printer, and there is no guarantee that the printer will work when you're done. With the cost of these printers so low today, you're usually better off buying a new printer, even if that means you've just wasted $60 on new ink cartridges. We discuss printer troubleshooting later in this tutorial.

Knowledge Base Searches

The best way to search a knowledge base, and for that matter, the Internet, is to use few keywords to start with. Do not use "and," "or," "the," and so forth. If you get too many responses, you can narrow the search with exact phrases. (Here you can use the aforementioned small words.) If you get too few responses, or none at all, broaden the search with fewer keywords. Also realize that many sites' search engines don't work well. Sometimes you won't get anything no matter how you search.

To reach Microsoft's Knowledge Base, go to support.microsoft.com Advanced searches can be very helpful. Click Advanced Search in the upper left-hand corner. You'll have options such as specifying the Microsoft product, searching for any of the words, all of the words, or the exact phrase, among others. Despite the fact that Microsoft's Knowledge Base has literally hundreds of thousands of articles, there will still be situations in which you can't find what you're looking for.

Tip Microsoft numbers its Knowledge Base articles with six-digit numbers. To search for a specific article, go to http://support.microsoft.com, click the Knowledge Base Article ID Number Search link under the Search the Knowledge Base link, and enter the article number in the box. In case this page changes, you should be able to find instructions on the support page.

Microsoft's Knowledge Base as well as other companies' knowledge bases are full of articles about hardware devices identified by brand and model number, or by chipsets, that have problems when used with certain versions of Windows or programs. If the problem could be related to hardware, it is a good idea to identify the device in the search dialog.

Searching for Error Messages

Perhaps the most important category of items to search for is the error message. Often, error messages are identified by numbers, but provide either cryptic descriptions or no descriptions at all. Therefore, the only way to find out what they mean is by searching the Internet or a particular site's knowledge base. Try searching on the manufacturer's Web site first, and try in different ways until you get a useful response. For example, if you get the message "Internal error 46," you could try searching for the full message text or just the number. You could also try searching for "error" or "error messages," and hopefully you'll get a list of error messages or a place to search for the specific message. Sometimes you won't find any information, but often you will. If you find nothing, search for the full text of the message on a search engine such as Google. It is usually helpful to use the search engine's advanced search function and select to search for the exact phrase. If you do, however, it is crucial not to make any typos; if you make even one typo, you might not get any hits.

Tip To make it easier to copy the exact text of error messages, as long as the computer is booted to Windows and is still running, you can use the <Print Screen> key. This key does not print directly; see tutorial 9 for instructions on its use.

To search for Microsoft error messages, go to support.microsoft.com, click Advanced Search and Help, select the product, or select All Microsoft products if you're not sure, enter the message verbatim (unfortunately, you probably won't be able to copy and paste the message), select the exact phrase search type, and then click the arrow. Also follow these guidelines if you get a "blue screen of death," officially known as a stop error. For more information on stop errors, see tutorial 2.