1 TYPES OF COMPUTER SYSTEM ERROR There are several errors in a computer from the point you open it upto the point you reach the stand by window (reaching standby windows means boot process has no error). Below is a list of computer errors. 1. No Video Output - When you open your PC, nothing shows up in your monitor and the LED indicator of your monitor is flashing in yellow color. 2. No Video Output - Same as number one but now the LED indicator of your monitor is in steady orange color. 3. Doesn't Boot - When you open your PC it will show the processor’s brand and/or the motherboard’s brand but doesn't continue. Usually this error will result to system restart over and over again. 4. Never Ending Loading of Operating system - The computer opens up then boots but when the operating system loads it, doesn't continue and it will take a longtime if you're going to wait for it to load. 5. Lots of pop up windows showing on standby mode - This also happens even if you try disconnecting your computer set from the internet. This is what we called aftershock virus which will continue to run even if internet is disconnected. 6. Lots of hardware installation windows appear - This happens even if you try installing the hardware. When you restart your set it will happen again. 7. Safe mode doesn't work - When you try going to safe mode, all you will see is a list of files in Command prompt style. 8. Keyboard and mouse system restart - This will happen only in standby mode, when you move your mouse or type something, your system will automatically restart and the worst part is it will delete a file at random. 9. Sound on/off error - Upon loading the operating system, you will hear a loading sound and then the sound stops, when you try running an audio file, no sound will be heard. 10. Application causes system to restart - Just like the mouse problem, when you open a program that will take the whole screen like for example a game and/or a program applications, when you close it, it will cause your system to restart. Aside from the common computer errors, computers also can have different Operating System (OS) errors. OS errors can be classified into various categories such as: 1. System errors – These are moderately dangerous types of errors among those that can pop up on your PC. System errors are caused by malfunctioning hardware components, corrupted operating system modules, etc. 2. Runtime errors – Runtime errors are caused by corrupted or malfunctioning system files or software executables. Most runtime errors cause the application that caused it to shut down. However, more serious runtime errors may cause the system to become unstable or unresponsive, suggesting that you should restart your computer. 3. Stop errors – Stop errors are caused by corrupted hardware, especially malfunctioning RAM modules and bad sectors on hard disks. Stop errors can be difficult to resolve at times. 4. Device Manager Errors – These are usually caused by corrupted driver files or malfunctioning hardware components. In case of the former cause, the problem is often solved by reinstalling or updating the drivers. However, the latter cause can often be solved only by replacing hardware components. 5. POST code errors – POST code errors are caused by malfunctioning hardware components, and are characterized by short beep sounds from the tiny internal speaker of your motherboard. POST code errors occur when you press the power button to turn on your PC.
2 6. Application errors – These can happen at any point of time. As the name suggests, these are caused by applications while those are running. These are commonly caused by glitches in the program code itself. These are normally resolved by updating the program to its latest version. 7. Browser Status Codes – These are caused by problems faced by browsers when trying to access a website. These can be caused by misplaced web pages in the server of the website itself, or due to connection problems. For instance, a 404 error would indicate that the browser is trying to access a webpage that does not exist in the specified location. DIAGNOSING COMPUTER SYSTEMS PC Diagnosing Probably the most frustrating problem computer users run into are startup problems, where your computer won’t boot. Equally annoying are error messages you constantly run into during your computer’s startup process. In this module, you will be given a few tips on how you can avoid some of the most common problems that happen right after your computer is turned on. Here you will learn the basic troubleshooting.
Trial and error: When you find a faulty component in your computer, check it with the other computers so that you can make sure whether the fault is in the component or not. Check cables: In case of any device failure, check all the cables of your computer such as data cables, power cable, internal circuitry cable and make sure that all these are plugged in and working fine. Hardware settings: Check the hardware settings in the CMOS and in the device manager of the system and make all the device drivers up to date and all the cards are plugged in properly. Notice changes: When you notice a software or hardware error in your computer, determine what was changed before the problem occurred. Event viewer: In the event viewer, you will find the error or warning messages associated with any faulty hardware or software. Make notes: Troubleshooting is a useful skill and we can learn a lot when we face any kind of troubleshooting in our computer. Make notes including the error messages and their solutions, so that you have a record on how a certain problem occurred and how did you solve it.
Common PC Problems and Solutions You are working away at your computer when suddenly, an error message – or worse, your computer comes to a screeching halt. Here are the common computer problems and solutions that can help you. Steps 1. Check the POST. POST stands for Power On Self-Test. This is generally the first or second thing that appears on a computer after turning on the power. This appears before the operating system begins to load. The POST will display any problem found with the hardware that makes the computer unable to boot. POST may also display problems with hardware that allow the computer to boot, but not operate at its full capacity during operation. 2. Notice the load time of the OS (operating system). A longer than usual load time may indicate errors in the hard drive. 3. Notice any graphics problems once the OS has loaded. Reduced graphics may indicate driver failures or hardware failures with graphic cards. 4. Perform an auditory test. An auditory test is a simple, but still effective way of judging how a computer is working. With the computer on and running, play any decent length audio file (usually above 30 sec.) If the audio is choppy or slow, it usually means that the processor is working at an elevated level, or there is not enough RAM to run all programs loading. Changing the startup sound is a great way to apply this test. Another issue associated with choppy sounds is PIO
3 (Programmed Input/Output) Mode. This affects how the hard drive reads and writes data from a drive. Switching to Direct Memory Access (DMA) allows for faster reads and writes, and can sometimes repair choppy audio. 5. Check any newly installed hardware. Many operating systems, especially Windows, can have conflicts with new drivers. The driver may be badly written, or it may conflict with another process. Windows will usually notify you about devices that can cause or have any problem. To check this use the Device Manager, this can be accessed by entering the Control Panel, clicking the System icon, clicking the Hardware tab, and clicking on Device Manager. Use this to check and arrange the properties of hardware. 6. Check any newly installed software. Software may require more resources than the system can provide. Chances are that if a problem begins after software starts, the software is causing it. If the problem appears directly upon startup, it may be caused by software that starts automatically on boot. 7. Check RAM and CPU consumption. A common problem is a choppy or sluggish system. If a system is choppy it is good practice to see if a program is consuming more resources than the computer can provide. An easy way to check this is to use the Task Manager, right click on the taskbar select Task Manager, and click the Processes tab. The CPU column contains a number that indicates the percentage of CPU the process is consuming. The Memory Usage column indicates how much memory a process is consuming. 8. Listen to the computer, if the hard drive is scratching or making loud noises, shut off the computer and have a professional diagnose the hard drive. Listen to the CPU fan, this comes on a high speed when the CPU is working hard, and can tell you when the computer is working beyond its capacity. 9. Run a virus and malware scan. Performance problems can be caused by malware on the computer. Running a virus scan can find any problem. Use a commonly updated virus scanner (such as Norton Antivirus or Avast! Antivirus) 10. Check for the problem in safe mode. To enter safe mode, press F8 repeatedly during POST (this works on most systems). If the problem persists in safe mode, it is a fair bet that the operating system itself is to blame. Common Trouble shooting for Computer Units 1. 2. 3. 4. 5.
Double check the power connections. Voltage regulator and power supply could cause power failure in the computer unit. Check the power cords and cable connectors in your computer unit. Unseated card. Loose cards could cause malfunction. Check the boot sequence configuration in the advance BIOS (Basic Input/Output Unit) setup.
Diagnosing Network Connection Things to look for if a PC is connected to the internet or network: First, check the cable connecting to the network card into the network hub. Check the back of the computer to see if the network card light is on Check the network cable (use cable tester) Check the network hub (use multi-tester) Things to Consider: There are many devices, parts, cords, and connections on a computer, which means that there are many possible problems that could arise. In addition, your computer uses a variety of software, which can also cause problems. However, no matter what the problem is, you can use the following tips to help you find a solution:
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Always check the cables: Many computer problems are related to an issue in the cables and connections. The easiest first step you can take to troubleshoot most problems is to check all related cables and connections. Isolate the problem: If possible, try to isolate the problem. For example, if you can't get the cursor to move on the screen, try to determine if the issue is with the mouse. If you have an extra mouse, you can alternate devices to see if the one plugged in is the issue, or use the arrow keys on the keyboard to help determine if the mouse is the source of the problem. When trying to isolate the problem, only make one change at a time.
Figure 7. An error message
Take notes about error messages: If your computer gives you error messages, be sure to write down as much information as possible. If the basic troubleshooting steps don't work, you may need the information you have taken. Remember the steps you've taken, or write them down: Once you start troubleshooting, you will want to remember what you have done, so you don't repeat yourself. If you can't remember it, then write it down. If you end up asking someone for help, it will be much easier if they know exactly which steps you've taken.
Simple Solutions to Common Problems Most of the time, problems can be fixed by using simple troubleshooting techniques, such as closing and reopening the program. It's important to try these simple solutions before resorting to more extreme measures. If the problem still isn't fixed, you can then try other troubleshooting techniques, such as reinstalling the software. Program Runs Slowly or Isn't Working Right
If a program is running slowly or otherwise isn't working right, the first thing you should try is closing the program and re-opening it. You can also shut down your computer, wait a few seconds, and boot it up again. Some minor problems will work themselves out when you do this. Check with the company for any known problems or updates to the software.
Figure 8.Checking for updates
5 Program is Completely Unresponsive
If a program has become completely unresponsive, you can press (and hold) Control+Alt+Delete on your keyboard to open the Task Manager. You can then select the program that isn't working and click End Task. If you are using a Mac, you can press Option+Command+Esc to open a similar dialog box.
Figure 9.The Task Manager Problems Starting or Shutting Down the Computer
Figure 10.Resetting a surge protector
If your computer does not start, begin by checking the power cord to confirm that it is plugged securely into the back of the computer case and the power outlet. If it is plugged into an outlet, make sure it is a working outlet. Often, this will require you to plug a lamp or other electrical device into the outlet to make sure it is receiving power. If the computer is plugged into a surge protector, verify that it is turned on. You may have to reset the surge protector by turning it off and then back on. You can also plug a lamp or other device into the surge protector to verify that it is on. If you are using a laptop, the battery may not be charged. Plug the AC adapter into the wall and then try to turn on the laptop. If it still doesn't start up, you may need to wait a few minutes and then try again.
6 "Non-System Disk” or “Disk Error" Message If you get this message when you boot up your computer, it usually means there is a CD, DVD, USB flash drive, or floppy disk in your computer, which is interfering with your computer's booting process. Remove the disk from the drive and restart the computer.
Figure 11.The Non-System Disk or Disk Error Message Windows Shutting Down Message Will Not Disappear Sometimes Windows will freeze during the shutdown process. If this happens, the Windows is Shutting Down message screen will stay active on your screen. To finish shutting down the computer, press and hold the power button for about 10 seconds, or until the computer turns off.
Figure12.The Windows shutdown screen Computer Begins Randomly Rebooting or Crashing Check for overheating. Make sure the vents in the case are not blocked. Confirm that there is good air flow around the computer. Update your antivirus software and scan for viruses.
Figure13.Virus Scanning
7 Problems with the Monitor and Speakers No Picture on the Monitor Confirm the computer is turned on. Check the brightness control, located on your monitor or your keyboard, and make sure it is not set too low. Check the connections for the monitor and surge protector, and make sure the surge protector is turned on. Figure 14.Cable plugged into monitor Monitor Goes Blank Periodically
You may have the screensaver enabled. If the screen saver is enabled, just move your mouse back and forth and your original screen will appear. You can change the screensaver settings by going to your Control Panel (or your System Preferences if you're using a Mac).
Figure 15.Opening the Control Panel
No Sound
Figure 16.Adjusting the sound volume on a Mac
Check the volume control on your computer. In Windows, the sound icon will usually be on the taskbar, and you can also access the sound options in the Control Panel. On Macs, the sound options are found at the top of the screen or in System Preferences. Most media programs (such as iTunes or Windows Media Player) have a volume control, which will need to be turned up. Make sure the speakers are turned on, if using external speakers.
Make sure external speakers are connected to the correct audio port or a USB port. If your computer has color-coded ports, the audio output will usually be green.
Connect headphones to the correct audio port and determine if sound is audible from the headphones.
Searching the web for a solution If you still haven't found a solution to your problem, you may need to ask someone else for help. Try searching the web for the problem that you're having, as other people may have had similar problems. Also, if you have a friend or family member who knows a lot about computers, they may be able to help you. Keep in mind that most computer problems have simple solutions, although it may take some time to find them. For very difficult problems, a more drastic solution may be required, such as reformatting your hard drive, reinstalling programs, or reinstalling your operating system. If you're not a computer expert, it's possible that you could make the situation worse, so it's best to consult a professional if you think a drastic solution is needed.
