The Troubleshooting theory

1. The Troubleshooting theory 902 Exam: Given a scenario, explain the troubleshooting theory MM Video 3:35

2. Computer Problems • Troubleshooting computer problems is a part of the computer technician’s role • Before you can fix a computer problem, you need to identify its cause • Expert troubleshooters use a systematic method to solve any computer problem • Every day there will be new problems to solve • Then ensure the steps you take successfully resolve the problem • Following this approach helps identify and resolve problems as efficiently as possible

5. To diagnose and troubleshoot a problem appropriately, you should perform the following steps in sequence: • Interview the user, identify the problem, and perform a backup • Establish a theory of probable cause • Test the theory to determine the cause • Establish a plan of action and implement the solution • Verify full system functionality • Document your findings, actions, and outcomes

6. Step 1: Identify the Problem • Some good questions to ask the user: • Describe the problem. What error messages, unusual displays, or failures did you see? • When did the problem start? • What was the situation when the problem occurred? • What programs or software were you using? • Can you show me how to reproduce the problem? • Has someone else used your computer recently? • What system changes have been made?

7. Step 1: Identify the Problem • Many problems occur due to recent action, so its important to find out from the user if anything has changed • Think of the user as a partner in your quest to resolve the problem • If the user is in an environment with other users, its good to find out if they’re having the same problem When you try to access Google.com, your computer contacts its DNS server and asks for Google.com’s IP address. You can try accessing a website at its IP address directly, which bypasses the DNS server. If the IP address method works but you still can’t access google.com, it’s a problem with your DNS servers. • If not, the problem is likely with that user’s system, but if its affecting all users, the problem is likely a network problem If you see packet loss (in other words, if the web server didn’t respond to one or more of the packets you sent), this can indicate a network problem. • Once you identify the problem, it’s important to back up the computer’s hard drive to ensure no data is lost

8. Step 1: Identify the Problem • When restarting a computer or when a computer is switched on, it runs a power on self test (POST) • POST is a useful tool for determining problems with system hardware • A good practice is to restart a computer so it’s in a clean state before troubleshooting further • If the POST detects a problem, the BIOS may give you a visual message or audio response (beep codes) • If the POST completes successfully, you’ll need to gather more info from the user

9. In middle school or high school you learned about the scientific method • Scientists develop a hypothesis, test it, and then figure out if the hypothesis is valid Step 2: Establish a Theory • Troubleshooting involves much the same process • Theories can either state what can be true or what can’t be true • Start eliminating possibilities and eventually the only thing left is what’s wrong (or the issue) • Start broad and narrow your scope

10. Step 2: Establish a Theory • The info a user provides can help with isolating the probable cause of a problem • Verifying the actions that a user performed before the problem happened may reveal the problem type • You may find that the issue is hardware related, software related, or user error • Make your best guess as to the source of the problem • Example: If video does not work, a best guess is the monitor cables are loose or the monitor is turned off

11. Once you identify the problem and possible cause of the problem, continue the process and test your theory Step 3: Test Your Theory • Testing your theory involves: • Checking hardware and software configurations • Checking Device Manager • Checking Vendor documentation • Checking Log files for entries related to the problem • Isolating the problem • Checking that the system is connected to a power source

12. CHECK HARDWARE • & SOFTWARE CHECK THE POWER SOURCE • You should ensure the power supply is connected and turned on • If a hardware problem is suspected ensure that the specific hardware is connected should be a first step • Power cables can become disconnected without the user realizing it and checking for obvious causes saves a lot of time • If a software problem is suspected check that the proper software and device drivers are installed

13. CHECK VENDOR DOCUMENTATION CHECK DEVICE MANAGER • Use Device Manager to check for conflicts between hardware devices and other problems with hardware • Vendor documentation often includes a list of problem symptoms and related fixes • Devices with an exclamation or found under other devices indicate that the device is conflicting with other hardware or the drivers for the device are not installed properly • Explanations can usually be found for status lights, indicators, and other visual clues that can help in the troubleshooting process

14. ISOLATE THE PROBLEM CHECK LOG FILES • A common technique is to strip the system down to the bare bones and then slowly rebuild the system to see if the problem comes back • You can use Event Viewer to access log files for the computer • Event Viewer is like the Windows “tattletale program” as it will show you what has happened in the last day, week, month, or more • To isolate a software issue, stop all nonessential services running in the background or start Windows in Safe Mode to eliminate unnecessary startup programs and drivers

15. Step 4: Establish a Plan of Action • Once you confirm the cause of a problem, the next step is to establish a plan of action and implement the solution • Consider different solutions and select the least invasive • If you implement a change and it doesn’t resolve the problem, you should undo the change • Example: If you suspect a faulty hardware component, exchange the bad component with one that you know is working • You may solve the initial problem but create a host of other problems if you don’t undo any changes made

16. Step 5: Verify full system functionality • Once you implement a solution, restart the system and verify full system functionality • It’s important to test the whole system, rather than only the hardware or software you’ve fixed or replaced • This ensures there has been no adverse effects on other parts of the system • Have the user check everything and verify functionality as well • Ask yourself this question: Could this problem have been prevented? • If so, instruct the user on what to do (set Windows to automatically install updates, advise on proper cooling)

17. Step 6: Document What Happened • It simplifies troubleshooting the next situation • Finally, document the actions you took in correcting the problem as well as the outcomes of those actions • Many companies use help desk software to record and track troubleshooting activity in tickets • Reasons to document include: • It helps with training others • It develops effective preventative maintenance plans