Lesson 5

CompTIA's troubleshooting method

1. Identify the problem. ○ Gather information. ○ Duplicate the problem, if possible. ○ Question users. ○ Identify symptoms. ○ Determine if anything has changed. ○ Approach multiple problems individually. 2. Research knowledge base/Internet, if applicable. 3. Establish a theory of probable cause. ○ Question the obvious. ○ Consider multiple approaches. ○ Divide and conquer. 4. Test the theory to determine cause. ○ Once the theory is confirmed (confirmed root cause), determine the next steps to resolve the problem. ○ If the theory is not confirmed, establish a new theory or escalate. 5. Establish a plan of action to resolve the problem and identify potential effects. 6. Implement the solution or escalate as necessary. 7. Verify full system functionality and, if applicable, implement preventive measures. 8. Document findings/lessons learned, actions and outcomes.

Troubleshooting Example

A computer system has a fault in the hard disk drive (cause). Because the disk drive is faulty, the computer is displaying a "bluescreen" (symptom). Because of the loss of service, the user cannot do any work (consequence).

Troubleshooting

A process of problem solving. Problems have causes, symptoms, and consequences.

Understanding the Problem

After you have gathered sufficient information about a reported problem, you must start to determine a theory of probable cause from analysis of the symptoms. This is a process of thinking about possible causes then eliminating those possible causes through testing to arrive at the root cause. Ultimately, the purpose is to complete the testing stage with a single probable cause, enabling you to search for and implement a resolution.

Ignore

As any software developer will tell you, not all problems are critical. If neither repair or replace is cost-effective, it may be best either to find a workaround or just to document the issue and move on.

Test the Theory and Escalate the Problem

As you devise different theories of cause, you will naturally also be testing them to see if they fit the facts. While "testing" follows "establishing" in the methodology, the process is iterative (establish a theory, test it, if it doesn't work, establish another theory). You might discover that the immediate cause of a problem is itself just the symptom of a wider problem with a different cause. The end result of this process, therefore, is to establish a root cause for the problem.

Screen is Dark During POST

Check that the monitor is plugged in and switched on, that the power cable and fuse are good, and that the cable from the monitor to the computer is properly connected. If you see a message such as "No sync," the cable is probably disconnected or damaged. If you can see a very dim image, check that the brightness control hasn't been turned all the way down.

Consider Multiple Approaches

If one troubleshooting method does not yield results, be prepared to try something different. For example, you might start by a process of questioning the obvious and step through the operating procedure but switch to a divide and conquer approach of testing each component in the process in isolation. You might also suggest workarounds. A workaround doesn't actually solve the reported problem but provides a way for the user to continue to work with the system. That way you can deal with the consequences of the problem quickly and give yourself more time to investigate the underlying issue.

Question the Obvious

If you can prove that there is no inherent fault (perhaps by failing to duplicate the problem on a reference system), make sure that the system is set up and being operated in the correct way. Step through the process of using the system or application making sure that you verify even the simplest steps by questioning the obvious, best illustrated by the age-old "Is it switched on?" question.

Replace

Often more expensive and may be time-consuming if a part is not available. There may also be an opportunity to upgrade the device or software.

Power On Self Test (POST)

The POST routine ensures that all the components required to start the computer are present. If the tests complete successfully, the computer may issue a single beep. Not many computers beep these days, so do not be worried if the computer boots silently.

Identifying The Problem

The first stage in the troubleshooting process which entails that you approach the problem logically. This stage utilizes multiple techniques. These being: Question Users and Determine Changes, Duplicate the Problem and Identify Symptoms, Approach Multiple Problems Individually, and Gather Information and Research Symptoms

Establish a Plan of Action

There are usually 3 ways to go about doing this, those being repair, replace, and ignore

Duplicate the Problem and Identify Symptoms

This is part of identifying the problem. It is very helpful to be able to observe the issue as it occurs. You might be able to do this via remote desktop or by visiting the user, but if these are not practical you could test whether the problem can be repeated on a lab system or virtual machine. If the problem cannot be duplicated on a reference system, this points to some issue with the user's local environment. You can also ask the user to describe symptoms, such as error messages appearing on the screen, or ask them to navigate to the relevant log file and report on its contents

Approach Multiple Problems Individually

This is part of identifying the problem. When you start to investigate symptoms, you might discover symptoms of more than one problem. Perhaps a user has reported that a machine has lost Internet connectivity, and you discover that it has also not been receiving maintenance updates. The issues could be related, or one might be incidental to the other. If the problems do not seem to be related, treat each issue as a separate case. If they seem to be related, check for outstanding support or maintenance tickets that might indicate existing problems. It may also be the case that a user reports two different problems at the same time (often preceded by, "While you're on the line..." sort of statements). Treat each problem as a separate case. In most cases you should advise the user to initiate a separate support ticket.

Question Users and Determine Changes

This is part of identifying the problem. You will probably start by asking the user to describe the symptoms of the problem and the status of the computer, including any error messages or unusual conditions. ■ How many people are affected by the problem? This helps determine the severity of a problem. Clearly, if all users are affected, that is more serious than if only one user is experiencing the problem. ■ When did the problem first occur? This could help you identify possible causes of the problem. For example, if the problem occurred on Monday morning during sign in, then that might indicate that the user's password expired over the weekend. The user might tell you that the problem has been intermittent for the last three weeks, but that it suddenly got worse. Either of these responses might help you focus your troubleshooting. ■ What might have changed? This is a crucial question because often, problems occur after something has changed. Sometimes, the thing that changed might seem totally unrelated. For example, someone experiences a problem right after some desks were moved. This might indicate a cabling problem that has arisen after a cable was broken or unplugged. The change might be a configuration change on your network or on the specific user's computer. Rolling back that change might resolve the issue.

Gather Information and Research Symptoms

This is part of identifying the problem. Your main source of information about a problem is likely to be the user reporting it, but if this is insufficient to successfully troubleshoot, you may have to consider other sources. ■ Use a remote desktop tool to access the system or travel to the user to observe it in operation. ■ View system, application, or network log files. ■ Monitor other support requests to identify similar problems. Once you have gathered sufficient information it is possible that you are able to learn enough to resolve the problem. This is likely with simple issues, such as password lockouts. If not, during this classification stage, you will document the problem in your ticket system and provide as much background information as you are able to determine. This will help you, or a colleague to whom you might escalate the issue, resolve the problem. If you do not recognize the problem, use a product Knowledge Base or a web/Internet search tool to research the symptoms you have identified. Using support resources and web searches is discussed in more detail later in this unit

Divide and Conquer

This means that you try to envisage different problem areas. In computing, this might be like making the distinction between a workstation problem, a server problem, a storage problem, or a network problem. You then devise a testing routine to eliminate one or more categories of problem. This helps you more quickly identify probable causes. For example, if you suspect a physical cabling problem, try plugging the device into a different wall socket. If that makes no difference, the problem lies elsewhere.

Search Engine

a tool to help locate web pages. It may be designed to search the entire web for pages or to locate pages within a particular site.

Post Fails (No Beep)

check whether the power light has come on and whether the disk light is flickering and whether there is an image on the screen. You should also be able to hear some disk activity and the whir of fans inside the PC. If you can detect none of these things, there is a power problem. Check the power cable and fuse. If these are OK, then the problem is either with the computer's internal power supply or the electrical outlet (try plugging in a lamp to test).

Repair

determine whether the cost of repair/time taken to reconfigure something makes this the best option

Multiple Beeps in POST

the beeps specify where the problem is (and there may be an error message on the screen), but you will probably need to get help to diagnose and fix it. Do check that nothing is resting on the keyboard; if a key is pushed down it can cause this type of error.