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Page 1 1001 Hardware and Network Troubleshooting Study Guide for the CompTIA A+ Core Series Exam

How to Prepare for Questions about Hardware and Network Troubleshooting on the CompTIA A+ Core Series 1001 Test

General Information

Over one-fourth (27%) of the CompTIA A+ Core Series 1001 test is devoted to questions about this topic, so you’ll need to know the content well. In addition, all of these questions will relate to a scenario given in the question introduction. So, you’ll need to decide what you would do in that situation, relying on your knowledge of proper procedures and hardware and network concepts.

Methodology (scenario)

Consider this situation:

“After arriving at work and logging in to your system, you start looking over the trouble tickets that are in your queue. While triaging them, you receive a phone call from Mary in accounting. She cannot log in to the system and has a meeting in 15 minutes. She is very irate that she cannot access her files for this meeting and is unable to finish her preparations.”

What’s the first thing you tell her? How do you go about troubleshooting this? Ensure that you consider all corporate policies, procedures, and impacts prior to implementing any changes to any system.

Identify the Problem

While there are numerous avenues that can be taken for the situation above, the onus is on you, the technician, to identify the problem. Always remember, users don’t always tell you everything, especially when emotions are involved and the possibility of not being prepared for their supervisor is a looming possibility. Simply calming the user down a little can move the conversation in the right direction.


Be calm and ask questions to the user while attempting to identify any changes to the computer that might have been performed such as security patches, physical movement, etc. These can be simple to correct and have the user back online in moments. (for example, if the cleaning company physically moved the computer while cleaning, Mary’s network cable might have come unattached and she is no longer physically connected to the network.). Be sure to make a backup of her files prior to attempting any changes on the computer itself just in case there is a larger issue and her system cannot be recovered.


Consider all the changes that could affect the user (network, computer, power issues, external connection, user account, etc.) and how those changes can be involved in the problem. As an example, let’s say the Network team worked over the weekend performing an upgrade to the infrastructure (switch replacement) and neglected to plug all the cabling back into the switch (as simple as a cable falling behind the wiring channel and being missed). Mary might have been the one missed and now she cannot authenticate to the network, cannot access her files, cannot print to the network printer, and therefore cannot perform her morning functions prior to her meeting. These things happen daily and other teams can be conducting changes without regard to the effect on employees.


If Mary’s system is on the network but she cannot authenticate, then there are a variety of methods that can be used to verify and/or troubleshoot her issue remotely (possibly faster than getting to her work space). Obtaining her computer name and opening up her event viewer from your workstation can give a wealth of knowledge into why she cannot authenticate. Obviously, this will not work if she is physically disconnected from the network (first thing that should be checked). By opening the Event Viewer or Computer Management on your workstation, you can choose to “Connect to Another Computer” and enter her computer name (or IP address, if known) to open her event log. From there, choose Windows Logs and peruse the list of log files given. Starting with the Application, look for any errors (noted with a red circle around an exclamation point) or a warning (noted with a yellow triangle around an exclamation point). These are indicators that something is amiss and should be investigated further.

Develop a Theory

Keep it simple. Always question the obvious and don’t think something isn’t relevant. You might think it is common sense to be plugged into the network, but the user might not know this. Using your questioning ability, develop a theory (or two) regarding what the problem might be. Another point to remember when developing your theory is that someone, somewhere has possibly run into this issue already. The Internet can be your friend or your worst enemy and the ability to decipher what you glean from the Internet is a valuable resource.

Test the Theory

When you have your theory developed, you need to test it. On a time-sensitive issue, or if you know 100% that the theory is valid, then you can implement it based upon corporate policies and/or procedures. In a perfect world, you would be able to replicate the issue within a testing (or laboratory) environment for verification. This isn’t always the case and you should be ready to test your theory at a moment’s notice.

If Theory Is Confirmed

Only test one possible solution at a time and only make one change at a time. Sounds like a lengthy process? Yes, but if you implement multiple changes in one process how do you know which one worked and which one didn’t? Remember, keep it simple. If your theory is confirmed, then you can skip to the plan of action to implement your theory. If not, then it’s back to testing again. No worries, proper troubleshooting is an art.

If Theory Is Not Confirmed

You’ve tested your theory and the problem still exists. Step back and take a look at your theory to see what other avenues are available and develop a working theory regarding the next possible solution.

Plan of Action

Always remember: Your company’s policies and procedures take precedence and should be in the forefront prior to acting on any plan. The conclusion that you make might possibly affect the whole company, but that might also be needed depending on the breath of the issue. Does correcting the issue require downtime for the company or just a computer? Can that be scheduled around the users workday? Does it need to happen immediately? These are all questions that should be included in your plan of action.


When implemented, does your solution fully rectify the problem and return all systems to functionality? Does the user have access to all documents and functions? Is there any way to prevent these issues from arising again?


Documentation! We can’t express how important it is for issues to be fully documented. Everything that you have done from the moment the user contacted you to the moment the user was back online such as indications, findings, actions, outcomes, scenarios, etc. Your company should have a repository (also known as a knowledge base) to keep this information safe. It should also be possible to share among your peers in the event the same type of issue arises in the future.

Motherboards, RAM, CPUs, and Power (scenario)

Listed below are some of the more common symptoms of issues in this area. There are many different situations that can arise when these types of hardware components start failing. For example, let’s say Jim from the mailroom calls the help desk and states that his computer is running slow. What are some of the first questions you should ask him? Starting with the specifications of his workstation might be good. If he only has 2 Gb of Random Access Memory installed and is using a memory-intensive program, then that might be a cause for his slowness.

  • Unexpected shutdowns—These can be caused by hardware that’s failing or by adding new hardware that’s incompatible.

  • System lockups—They can be caused by something freezing up the operating system, such as a bad system or application process, or by using old software or driver versions. Maxed-out RAM can also cause a lockup.

  • POST code beeps—Errors in the Power On Self Test are associated with hardware components required to successfully boot the system. The cause of these could be problems with BIOS configuration or hardware.

  • Blank screen on bootup—BIOS or CMOS battery issues can be the root of this problem. Also check video signals.

  • BIOS time and setting resets—These indicate a problem with the BIOS CMOS battery.

  • Attempts to boot to incorrect device—This can be caused by a problem with the boot settings within the BIOS.

  • Continuous reboots—These could be related to BIOS problems or OS problems. Problems with a bad driver may also be responsible.

  • No power—Power outlet or power supply issues are usually the cause of this.

  • Overheating—Problems with the fan, heat sink, dust accumulation, or something blocking the air circulation can all cause a device to overheat.

  • Loud noise—This can be a result of loose hardware or issues with the hard drive.

  • Intermittent device failure—Hardware is usually responsible for this, in the form of a bad hardware installation, overheated components, hardware going bad, or hardware not fully connected to motherboard.

  • Fans spin—no power to other devices—This can be caused by a problem with the motherboard. Also check the power supply.

  • Indicator lights—Indicator lights can inform you of certain problems going on with computer hardware or tell if there is activity or power coming from a certain connection point. Consult the computer’s documentation for more information about this.

  • Smoke—Smoke can indicate a blown capacitor.

  • Burning smell—Again, a bad capacitor or a burned-out hardware piece can be the culprit.

  • Proprietary crash screens—This could be caused by faults in the OS system files.

  • Distended capacitors—There could be a defective capacitor from manufacturer or overheating inside the case (bad fan)

  • Log entries and error messages—Can indicate a variety of issues from improper credentials to failing hardware.

Hard Drives and RAID Arrays (scenario)

Clicking, grinding, whining, whirring—these are all indications of failing hard drives. You won’t hear much from a Solid State Drive (SSD), but you may on a conventional hard disk drive that spins at an amazing speed (5400 rpm, 7200 rpm, 10000 rpm, and beyond). Below is a small list of indications of a hard drive beginning to fail (or having failed, in some cases). Server hard drives are a little more difficult to detect, as they are normally in a server room with other servers. These rooms can be very noisy. A good practice for server rooms is to turn off the overhead lights and watch the hard drive indicators. If you see an amber light, troubleshoot this server a little further. There are various software platforms that will notify the operator (regarding servers) of the “health” of the hard drive, but nothing compares to physically checking periodically.

  • Read/write failure— This indicates a dying hard drive and could happen if the read/write head crashes.

  • Slow performance— This can indicate that a drive has already failed or that there are errors on the drive files. There may also be issues with virtual memory.

  • Loud clicking noise— This can be caused by a mechanical failure within the drive itself.

  • Failure to boot— This failure could be a hardware or software issue, depending on what stage the boot process gets to before it happens. Check in BIOS settings for removable devices such as USB drive. Cables and connectors can also cause the problem.

  • Drive not recognized— Typically, this indicates a hardware issue with one of the drives. This could be a failed component, a data corruption issue, or an error in BIOS settings.

  • OS not found— This message indicates a software issue with loading the operating system.

  • RAID not found— This problem could be caused by issues with the RAID controller or the management software.

  • RAID stops working— This can happen in any RAID array that does not mirror data. It is usually caused by one of the drives failing.

  • Proprietary crash screens (BSLO/pin wheel)— This is known as the “blue screen of death.” On Windows, this is a stop error, and on Apple, you will get a continuous pinwheel on the screen. This typically indicates a fatal failure, such as a CPU dying or a burned-out part.

  • S.M.A.R.T. errors— This stands for Self Monitoring Analysis and Reporting Technology, and it includes multiple error categories known as SMART statistics. These can proactively see issues before a drive fails completely.

Video, Projector, and Display (scenario)

Consider this situation:

A call comes in to the help desk, the Chief Financial Officer (CFO) has started a meeting with the “C” level officers (including the Chief Executive Officer, CEO) in your company and the projector won’t power on. This has happened before and will happen again. What’s the next step?

Below are some of the more common symptoms to look for. Watch out, those projector bulbs can be hot!

  • VGA mode— This mode is similar to Safe Mode but for display issues. The PC boots with the minimum video drivers in use, which is helpful for troubleshooting.

  • No image on screen— This can happen if there is a cabling issue, or a connection is not seated properly.

  • Overheat shutdown— A shutdown of this sort could be due to problems with the video card or blocked airways for ventilation.

  • Dead pixels— This issue is typically related to the hardware, or the monitor itself. Replacement of the display is usually necessary to correct it.

  • Artifacts— These could be caused by problems with the adapter or video drivers.

  • Incorrect color patterns— Damaged cables or a damaged connection port on the PC may be responsible for this malfunction.

  • Dim image— This irregularity often has something to do with brightness settings on the display or with adapter issues.

  • Flickering image— This happens when there are damaged cables or a damaged connection port on the PC.

  • Distorted image— The system settings on your OS may be responsible for a distorted image. The refresh rate or resolution may be at fault.

  • Distorted geometry— This variance could be caused by display settings, video card issues, or magnetic interference.

  • Burn-in— This is caused when images stick on the screen and become permanent parts of the display. It could be caused by stuck pixels.

  • Oversized images and icons— If the resolution of the monitor does not match the system settings, this can be the result.