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
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.
Step 1: Identify the 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.
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
If not, the problem is likely with that user’s system, but if its affecting all users, the problem is likely 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. Step 2: Establish a Theory
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. Testing your theory involves:
Step 3: Test Your Theory
Once you identify the problem and possible cause of the problem, continue the process and test your theory
Testing your theory involves:
Checking that the system is connected to a power source
Checking hardware and software configurations
Checking Device Manager
Checking Vendor documentation
Checking Log files for entries related to the problem
Isolating the problem

12. You should ensure the power supply is connected and turned on
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 DEVICE MANAGER
CHECK VENDOR
DOCUMENTATION
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. You can use Event Viewer to access log files for the computer
ISOLATE THE PROBLEM
CHECK LOG FILES
You can use Event Viewer to access log files for the computer
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
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