Troubleshooting Common Hardware Problems – CompTIA A+ 220-1101 – 5.2

There are often common problems found when troubleshooting hardware issues. In this video, you’ll learn how to troubleshoot common hardware problems such as startup errors, Windows stop errors, power issues, overheating, and much more.


When you first turn on your PC, there are a series of diagnostic tests that occur. These occur in a matter of seconds. But they’re checking for very key components inside of your system. This power-on self-test or POST is designed to make sure that all of the main components of your system are available. So it will check to make sure that the CPU is active, that video is working properly, that your keyboard is operating, and that there’s memory installed in the system.

If any of these components are missing or not working properly, you’ll hear a series of beeps and perhaps even see information shown on the screen detailing the problem that the POST found. The reason that you get both a beeping sound and messages on the screen is that you could have a problem with the video that’s in the system. And if that’s the case, you won’t be able to see any error messages on the screen. So those beeps provide you with some feedback on what problems the POST process has found.

That means that you’ll hear different beeps for different types of problems. For the purposes of your A+ certification, you don’t need to memorize these different beep codes. And, in fact, different manufacturers use different beep codes. So memorizing the codes is not going to help you very much. Instead, you’ll want to look at the documentation for your motherboard, which will list every beep code and what that beep code is associated with.

If you start your computer and you get a blank screen with nothing else on the display, then you’ll want to listen to hear what those beeps are telling you. And those beep codes may tell you that you have a bad video adapter, maybe the memory is not installed in your system or it’s not working properly, or there’s no CPU or the CPU inside of the system has some type of fault. This could also be associated with a bad BIOS configuration. So you want to listen to those beep codes to know exactly which direction you should go to help troubleshoot this particular problem.

Another message you might see on the screen while you’re booting your system is that the date and time is either incorrect or has been reset. This is a function of the BIOS or basic input output system that’s responsible for keeping track of the date and time. The way that it’s able to maintain this date and time, even when you’ve unplugged your system, is through the use of a battery that’s installed on your motherboard. And if that battery has gone bad or all of the voltage has been depleted, then the system will not have any idea what the date and time might be. And you will have to manually set that every time you start your computer until you replace the battery on the motherboard.

Another problem you might see during startup is that your system tries to boot from a drive that is not the normal startup drive. The drives and their boot order are configured in the BIOS configuration. So you need to start your BIOS config. Look to see in which order these different boot drives are listed. And then, you’ll be able to either move these boot drives around or remove some from the list.

It might also be the case that you’ve left a USB drive plugged in and the USB drive attempts to boot prior to the primary storage drive. In that case, you would simply need to remove the USB drive, restart your computer, and it will begin to boot from the normal boot drive. At that point, your operating system can start. And you’ll get a message like this if things aren’t going well. This is a Windows stop error or what we commonly call a blue screen of death. And it’s telling us that something fatal has occurred. And you’ll need to restart your system to get things back up and running.

The official term for this screen is a Windows stop error. But we also refer to this as a Windows blue screen of death. This blue screen gives you information on why this particular error may have occurred. But you’ll have to restart your system to get your operating system running again. If this blue screen goes by very quickly and your system restarts, you can still go to the Windows Event. Viewer to see all of the information associated with this Windows stop error.

This is especially useful if you’re visiting a user who’s had this problem in the past. They didn’t write down any of the details on the screen. You can now go back to the Event Viewer to see exactly what happened at that time frame. Unfortunately, these problems don’t give a lot of information on this single page. And even the reference pages on Microsoft’s website don’t give a lot of detail on how you can resolve specific issues.

In those cases, you may want to contact the manufacturer of the computer or of the hardware that you’ve installed in the computer that’s causing this blue screen error. They may be able to use the debug logs and other information on your system to narrow down exactly why this problem is occurring on your computer. If you’d like to do more research on this error, you can visit the Microsoft website Windows.com/stopcode. And then you can use the stop code that’s on the screen to find out more information about this error.

If you start reading through that Microsoft website, you’ll notice that there are many reasons why a blue screen may have occurred. It could be bad hardware in your system. You might have installed drivers that aren’t working properly with the operating system or maybe an application that’s not performing properly. If this is a new problem, you may be able to get a previous configuration installed so that your system is back up and running. So you could try the last known good configuration on your system, run a System Restore, or roll back to a previous version of the driver that you just installed.

You may find that your system is able to boot into Safe Mode but not able to boot into a full blown version of Windows. In that situation, it may help you narrow down where the actual problem may be occurring, since some drivers are loaded during Safe Mode and other drivers are not. If you’ve installed the new adapter card or any new hardware into your system, it might make sense to remove and reseat that component, just to make sure it’s making a good contact with the motherboard.

And if this is a problem that continues to occur, you may want to perform a full hardware diagnostics of your system. Usually, you can get a hardware diagnostics utility directly from the manufacturer. Very often, your UEFI BIOS will have a hardware diagnostics built into the BIOS itself. If you’re a Mac OS user, you may have run into a situation where you’ve been moving your cursor around the screen or using a particular application and then suddenly, the cursor turns into what appears to be a spinning beach ball. We refer to this as the spinning ball of death. But the official name is the Mac OS 10 spinning wait cursor.

This is giving you feedback that something is happening on the system. And whatever is happening has to complete before you are able to regain access to the operating system. In some cases, that’s spinning ball may appear for a moment. And then it will go back to the normal cursor. But there are times where the spinning ball will start but it will never stop. It will simply spin and spin. And you’ll never be able to regain access to the operating system. In those cases, you’ll have to completely power down the system and power back on to be able to log back into the OS.

There are many reasons that a spinning weight cursor might appear on your system. It might be a bug in an application. You could have bad hardware, or bad memory, or it may be slow paging information out of memory and to the storage drive or back again. In all of these cases, we have to wait for that process to finish before the ball will disappear and you get your cursor back in the operating system. If the cursor never reappears and you have to restart your system, you’ll want to go to the console logs in Mac OS to see if you can find more information about why this particular error occurred.

One common problem on a desktop computer is a screen that stays black. There’s nothing on the screen, no writing, no messages, and no feedback as to where the problem may be occurring. When we first see a problem like this, one of the first things you should check is all of the cabling. Do we have a power cable plugged into the back of the monitor? And is it properly connected to the video output of your computer? This is probably the majority of issues that you will have with the black monitor. Because either one of those cables being disconnected will cause the screen to be completely black.

You’ll also want to check the input option on the front of the monitor. There’s usually a button or setting where you can configure which interface on the monitor is designed to be the input. You might connect to this monitor over an HDMI connection, a DVI connection. a DisplayPort connection. There might be a VGA interface. And any one of those can provide video signal for the monitor. But if you’ve not told the monitor which one of those interfaces is in use, the monitor will simply stay black.

Sometimes there is information on the screen, but it’s very difficult to read, the screen is very dim. Most monitors will have a brightness and contrast control. So you can adjust those to see if you can make that dim image a little bit brighter. You might also want to try replacing the monitor with another monitor that is working properly. This will help identify whether the problem is specific to the monitor or whether the problem occurs even with a known good monitor in use.

And if you happen to see information on the screen but suddenly everything goes black once Windows loads, then you might want to tell Windows to start up in VGA mode. This is a generic graphics mode that is able to work across almost every monitor on the market. So by using VGA mode, you could test to see whether the issue is with a driver or whether the issue is with the monitor itself.

If you push the power button on your computer and nothing happens, then you probably have an issue relating to power. It may be that no power is coming from the outlet. So you can grab your multimeter or handheld tester to see if this outlet really is providing power to the power supply. You’ll then want to check the power supply, make sure that everything is cabled properly, and that you have all of the switches turned on. And, of course, you could use your multimeter inside of your system to see if it’s receiving DC power from the power supply.

You also want to look very carefully to see if anything inside of that computer is receiving power. For example, you may find that the fans are spinning inside of the system, but the motherboard and everything else seems to be inoperable. If that’s the case, you may want to see where the fan power happens to be connected. Are the fans connected directly to the power supply or are they providing power from the motherboard? This might allow you to narrow down whether the issue is with something on the motherboard or something relating to the power supply.

Along those lines, we may want to check the power-on self-test process to see if it identifies any problems during the startup, which might indicate a problem with the motherboard. The fans that are inside of your system don’t need a lot of voltage to spin. So if they’re getting just a little bit of voltage from the power supply, they may be working properly but your motherboard may not be receiving enough voltage to start up and have your system work normally.

If you are able to start your operating system but you’re still finding that it is very slow and sluggish to operate, then you might have a problem with a process or an application running on your system. To be able to get an overview of performance, you may want to start Task Manager and view the CPU utilization for each individual process. There’s also a Performance tab. And clicking that brings up a list of CPU utilization for all processes on your computer. Using both of these screens might be able to provide you with information on how much the CPU is being used.

And if you’re seeing information like this, where there’s very little utilization, then it could be that this sluggish performance is being caused by something else. It could be that there’s a process behind the scenes using more resources than you expect. That’s certainly the case if Windows Update begins its process of downloading updates and installing new patches. This might cause your system to slow down but not give you any information on the screen as to why it’s being very sluggish.

If your storage drive is filling up and the operating system is not able to write files to that drive, this could also cause the operating system to perform poorly. So you may want to check your storage drive to see if you have available space for Windows to work properly. You might also want to consider running a defragmentation if you’re using a hard drive. Some systems will run slower if certain features are in place. For example, if you’re running a laptop and you unplug from main power and run on battery power, many laptops will automatically throttle down the CPU to run slower and, therefore, use less battery.

Some desktop systems will also monitor for temperature. And when temperature rises inside of your system, it will also begin to run the CPU slower so that your system will be able to cool down. And there may be times when the anti-virus or anti-malware software running on your system is processing or searching through a number of files. And that may also cause your system to appear sluggish.

Every component inside of your system is contributing to the overall heat that’s generated by your computer. This heat could be caused by the CPUs that are on your motherboard. You might have an external video adapter or the memory modules themselves may be creating heat. The majority of systems is able to cool down all of these components using fans and air that’s blowing through the system.

You might also see heat sinks that are connected to these components to help dissipate that heat into the cooler air. But all of these need to be cleaned to be able to properly perform that cooling function. And if you have a lot of dust or dirt on your system, it will affect the ability of that system to remain cool. It’s sometimes difficult to be able to know exactly how warm it might be inside of your computer. So you might want to use a third-party utility such as HWMonitor to be able to see exactly what the temperature is inside of your computer.

Hopefully, the back of your computer doesn’t look like this one. This one has a lot of dust. And it certainly contributing to overheating on this system. To solve this problem, we’ll want to vacuum up all of the dust that’s on the back of this system so that we can regain an airflow through the computer case. It’s often said that our computers run on smoke. And if we happen to let the smoke out, our computer stops working. That could certainly be the case if a component inside of your system fails and you start to see or smell smoke coming from your computer.

The moment you smell something that may have burned or you see smoke coming from your system, you will want to disconnect from the power source immediately. It’s very possible that you can avoid any additional damage by removing any of those power sources. You’ll then want to take the cover off of your computer and look at your motherboard very carefully to see if you can find where that particular component may have failed. It may be possible to replace that single part that’s failed or you may have to replace the entire motherboard.

One of the more challenging problems to troubleshoot is when you’re using your computer and then suddenly, it goes black. You have no idea why your system failed. There were no error messages and there was nothing on the screen that can give you any clue as to what just happened to your system. If you’re running Windows, you may want to restart the system and look into Event Viewer. You may find that Windows wrote some information into the log just prior to powering down.

That error message may tell you that the system saw an excessive amount of heat on your system. And it shut down your computer to protect all of the components on your motherboard. If that’s the case, you may want to check the fans and heat sinks in your system and make sure that the airflow is moving through your system properly. You might also want to do some additional monitoring to see what the temperatures are inside of your system so that you can get some feedback on why these high temperatures may be occurring.

But the problem may have nothing to do with heat. It may be a single component on your system that is failing and causing the entire system to abruptly power down. You may be able to see some information in Device Manager, especially if that component is not working properly. And you’ll want to run a diagnostics of the hardware to see if you can narrow down where this problem might be. Because you’re provided with such little data to help you understand where this problem may be occurring, you may have to perform detailed diagnostics and begin removing anything that might be good from the equation.

Once you eliminate items that are working properly, you can move your focus towards devices that may not be working correctly and perform additional diagnostics of those components. There may be times when Windows has identified a problem, but it has no information on what the problem might actually be. And you might get a message like this that says, Windows Explorer has stopped working. And Windows is checking to see if it has identified why this particular problem occurred.

It may be that you get a dialog box like this one that at least tells you that a problem occurred. Or it may be the application disappears from the screen completely without any error message. In both of these cases, it might be worthwhile to look at the Event Viewer inside of Windows to see if it can give you more details about why this application may have failed.

Another great utility inside of Windows is the Reliability Monitor. This will take all of the information that’s been saved in your Event Viewer and provide you with a graphical overview of how your system has been performing. This will break down day by day how your system has been performing. And it separates out the problems into application failures, Windows failures, and other issues. If you think the problem is related to a specific application, you might want to try uninstalling that application and then reinstalling the latest version of that app on your system.

Here’s a better view of Reliability Monitor. You can see there have been miscellaneous failures on the 20th. And there are some application failures listed on the 2nd and the 6th. There’s also details on all of these errors. And you can break down what application failed, what the messages were, and it even gives you an option to check for a solution for that particular problem.

Something you do not want to hear from your computer is any type of grinding noise. If there are sounds coming from your computer, then it’s probably the hum of a hard drive or the fans that are spinning on your computer case. But you should never hear something grinding or making an abrupt noise inside of your computer system. It could be that there are components inside of your case that are not properly fastened– if you put an adapter card in but didn’t screw it down properly. Or it could be that a heat sink may have popped off of a component. And now it’s moving around inside of your case and needs to be replaced.

If you have a hard drive inside of your system, it could be that the scraping noise is coming from the hard drive itself. That is certainly a very bad error to have on a hard drive. And hopefully you have some backups that you can use to restore any data that may have been lost. If you hear an ongoing oscillation or clicking noise, it could be that something is lodged itself in one of the fans that’s cooling your system. So make sure all of your fans are clean and clear and that you can spin all of them without any type of resistance.

And if the sound you’re hearing is more of a popping noise instead of a grinding noise, it’s very possible that you have a problem with a capacitor that’s on your motherboard. You often have to look very carefully at a capacitor to see if it may be having a problem. For example, this capacitor here has a very flat top and everything looks perfectly normal with that particular component. But right next to it is a capacitor that is bulging out just a little bit on the top. And that certainly speaks to a capacitor that may not be operating properly.

Here’s a view of some other capacitors. This one looks pretty good. The one on the left side looks OK. But you can see this one in the middle seems to be bulging just a little bit. And in extreme cases, the entire capacitor top may blow off the top, leaving the inside of the capacitor shown on the motherboard. These would certainly be capacitors that would need to be replaced. And this is one where you may want to look at other components on the motherboard and make sure there’s no damage with any of those components either.

One very frustrating error that can occur in an operating system is that everything suddenly freezes. The mouse doesn’t move, nothing changes on the screen. But there’s no error messages giving you any feedback as to why your system is suddenly frozen up. When the system freezes this way, look for anything that may be still responding to you. Look for any hard drive lights, maybe they are status lights on the front of the computer. Maybe you could hit the number lock button and see if that button is toggling on and off. Or try hitting Control Alt Delete to see if you can regain access to the operating system.

We also have to think about what may have changed on this system recently. So if you’ve installed new hardware or installed new drivers, it may be that those new additions are causing this lock-up issue. You’ll also want to see how the resource utilization might be on your system. If you happen to run out of storage space or out of memory, this could cause the operating system to have no resources available and simply hang the entire OS.

If none of these happen to solve this lock-up problem, then it may be time for a complete diagnostics of the hardware to ensure that everything inside of your system is working properly. One challenging troubleshooting task is when you power on your computer, it seems to start up normally, and then suddenly restarts the entire system and begins from the beginning again. And this happens over, and over, and over in a cycle.

In those situations, you need to document where the actual reboot process is occurring. Do we have BIOS messages that are appearing on the screen? Do we see a Windows splash screen as it’s starting up? Do we see any part of the operating system as its beginning? This might help you determine if the issue is related to the configuration of your BIOS or if there’s something in the operating system that’s preventing it from booting properly.

If you’ve recently installed a new driver or updated any part of your operating system, you might want to start with the F8 key and choose boot from last known working configuration. This will remove any changes you’ve recently made and go back to the last known good login configuration that you had on that system. You might also want to try Safe Mode, since only a subset of drivers are loaded during the Safe Mode configuration.

If your system does start successfully in Safe Mode, you may want to start the system properties configuration, change the settings, and disable the automatically restart option. This means when a stop error or a blue screen appears on your computer, you’ll have time to see exactly why that error has occurred and document everything that might be on the screen. And it may be that these reboots are being caused by hardware that’s going bad on the system. So you may be able to remove an adapter card or swap some memory and have your system back to normal operation.

If you start your computer and you notice that the date and time is not correct, it may be that the battery that’s on your motherboard has failed. This battery on your motherboard is responsible for maintaining the date and time when your system is unplugged. So if you start up your system and the date and time are not correct, it’s probably because this battery is discharged. Until you replace the battery with one that’s operational, you’ll get this error message every time you restart your computer.

And in some cases, even manually changing the date and time cause it to go back to the incorrect date and time each time you reboot. If you’re looking to clear the BIOS configuration, you may think that removing the battery would cause the BIOS to reset. But these days, the BIOS configuration is written to flash memory that’s on the motherboard. And if you want to remove or erase that flash memory configuration, you’ll need to short a jumper and restart your system.

Simply removing the battery from the motherboard on newer computers does not reset any part of the BIOS configuration. Here’s an example of that battery on the motherboard. These are relatively common batteries, so it’s very easy to pop these out of the slot, replace it with a new battery, and restart your system.