LIST OF POSSIBLE FAULTS ON A COMPUTER THAT COULD BE EASILY IDENTIFIED FROM EXTERNAL SYMPTOMS

COMMON KEYBOARD PROBLEMS & SOLUTIONS

The keyboard is a vital link between a computer user and the screen. If the keyboard stops working, that does not necessarily mean you need to replace it. Users can solve some common keyboard problems.

You can solve some problems with your computer keyboard.

Hardware

If keys stick or certain keys become unresponsive, dust and dirt are likely causes. Turn the keyboard upside down to try to release the dirt trapped inside. If that doesn't fix the problem, use compressed air to spray a jet of air between the keys, releasing any debris.

Software

Keyboard layouts, set by the operating system, use different alphabets and accented letters for different languages. If you type a key and the wrong letter or symbol appears, your system may be using the wrong keyboard layout. Change the keyboard layout preferences back to your desired layout.

Settings

Laptop computers often have a "number lock" setting that turns a section of the keyboard into a numeric keypad. If some letters on your laptop keyboard produce numbers instead, check that you haven't turned on this setting by mistake. A keyboard shortcut usually controls it.

HARD DISK DRIVE FAILURE

A head crash, one type of disk failure

A hard disk drive failure occurs when a hard disk drive malfunctions and the stored information cannot be accessed with a properly configured computer.

A hard disk failure may occur in the course of normal operation, or due to an external factor such as exposure to fire or water or high magnetic fields, or suffering a sharp impact or environmental contamination, which can lead to a head crash.

Hard drives may also be rendered inoperable through data corruption, disruption or destruction of the hard drive's master boot record, or through malwaredeliberately destroying the disk's contents.

Causes

Some hard disk drives simply fail because of worn out parts,^{[1][clarification needed]} others fail prematurely. Drive manufacturers typically specify a mean time between failures (MTBF) or an annualized failure rate (AFR) which are population statistics that can not predict the behavior of an individual unit.^[2] These are calculated by constantly running samples of the drive for a short amount of time, analyzing the resultant wear and tear upon the physical components of the drive, and extrapolating to provide a reasonable estimate of its lifespan. Hard disk drive failures tend to follow the concept of the bathtub curve.^[3] Drives typically fail within a short time if there is a defect present from manufacturing. If a drive proves reliable for a period of a few months after installation, the drive has a significantly greater chance of remaining reliable. Therefore, even if a drive is subjected to several years of heavy daily use, it may not show any notable signs of wear unless closely inspected. On the other hand, a drive can fail at any time in many different situations.

The most notorious cause of drive failure is a head crash, where the internal read-and-write headof the device, usually just hovering above the surface, touches a platter, or scratches the magnetic data-storage surface. A head crash usually incurs severe data loss, and data recovery attempts may cause further damage if not done by a specialist with proper equipment. Drive platters are coated with an extremely thin layer of non-electrostatic lubricant, so that the read-and-write head will simply glance off the surface of the platter should a collision occur. However, this head hovers mere nanometers from the platter's surface which makes a collision an acknowledged risk. Another cause of failure is a faulty air filter. The air filters on today's drives equalize the atmospheric pressure and moisture between the drive enclosure and its outside environment. If the filter fails to capture a dust particle, the particle can land on the platter, causing a head crash if the head happens to sweep over it. After a head crash, particles from the damaged platter and head media can cause one or more bad sectors. These, in addition to platter damage, will quickly render a drive useless. A drive also includes controller electronics, which occasionally fail. In such cases, it may be possible to recover all data.

The phenomenon of disk failure is not limited only to drives, but also applies to other types of magnetic media. In the late 1990s, Iomega's 100-megabyte Zip disks used in Zip drives were affected by the click of death, called so because the drives endlessly clicked when accessed, indicating the impending failure. 3.5-inch floppy disks can also fall victim to disk failure. If either the drive or the media is dirty, users may experience the buzz of death when attempting to access the drive.

 

WHAT ARE THE SIGNS OF CMOS BATTERY FAILURE?

Sign -1 Incorrect computer date and time settings. Also, the date/time keep getting reset even after you fix them in the BIOS. This is the most common CMOS battery failure sign.

Sign -2 Your PC occasionally turns off or doesn’t start.

Sign -3 Drivers stop working.

Sign -4 You may start to get errors while booting that say something like “CMOS checksum error” or “CMOS read error”.

Sign -5 Some weird hardware issues such as your computer not being able to locate the mouse, keyboard, or printer.

When the CMOS data can no longer maintain info on the bios for example when you look at the date and time let says that your CMOS bios says the following January51997 (System manufactured Date of Mother Board) and time9:00am and you change it to correct information it should stay save by the CMOS by the way if look at the desktop clock time should have change.

Press F1 to boot set up and F2 to Reset Boot Setup ( First boot devices goes to default as F loopy drive

So if u turn your computer the next morning and the date and change again then your battery is weak if not date and time should be same when you change it the1st time. here an article of CMOS battery behavior.

PROBLEMS WITH DESKTOP MONITORS AND LAPTOP SCREENS

Signs of PC Monitor Failure

Computer monitors are an essential element of every PC setup. Users can choose from older CRT (cathode ray tube) monitors, or modern flat-screen monitors such as LCDs (liquid crystal displays), high-efficiency LED (light-emitting diode) screens and plasma displays. Each type of monitor is subject to failure and may need replacement after a number of years.

Monitors may lose their ability to display color over time.

Not Powering Up

Some monitors may fail to power up even while plugged into a working outlet. The screen remains black and the status light fails to illuminate after pressing the power button. This can indicate a problem with the monitor's power supply or a loose connection within the monitor's housing. A new power supply may solve the problem, and is an easy fix for monitors with an external power supply. Faulty power cords can cause the same symptoms, so using a different cord to test the monitor is important to isolating the problem to the monitoritself.

Dim Image

CRT monitors have a tendency to become dim over time. The monitor may not be able to produce the full range of brightness that it once could, and images will begin to appear flat and dark. This indicates that the cathode ray tube is wearing out, which is an inevitable occurrence with this type of technology. New tubes may cost more than a new monitor, so tube replacement is not likely to be a cost-effective option. Adjusting brightness settings on the monitor, or through the computer's display settings, may help temporarily in producing a sufficiently bright image on an aging CRT monitor.

Image Distortion

As a monitor begins to fail, it may produce distorted images, These can take on a specific color tint, such as a yellow or green cast that adjusting the color settings can't eliminate. In other cases, an image will exhibit static distortion with lines of a solid color interrupting the image on screen. This may be due to a failure of the electronics, or a buildup of magnetic particles on the electron gun in a CRT monitor.

Dead Pixels

LED monitors are composed of thousands of tiny pixels, each of which can change colors rapidly to display an image. Individual pixels can begin to fail as an LED monitor ages. Dead, or stuck, pixels will stop displaying a range of colors, instead remaining a single color. These can be hard to identify depending on the screen image, but clusters of dead pixels can gradually become obvious and begin to interrupt viewing.

Screen Burn

CRT, LCD and plasma monitors are all susceptible to some form of screen burn. This occurs when an image remains on the screen for an extended period of time and becomes a permanent part of the screen. It may result in a ghosting effect; in some cases, actual images or text remain visible on the screen even when it is displaying another image. Screen burn is a matter of fatigue and indicates that a monitor has been overused without varying the image it displays.

Common Hard Drive Problems and Solutions

1. Corrupted Files

Corruption of system files usually occurs when the system is shut down suddenly, making it impossible for you to access your hard drive and thus your system. Some of the reasons for the corruption of the system files include power surges, use of malicious program, accidental closure of a running program and improper shutting down of the PC.

The solution for this problem is to make sure that you close down all programs that are running before commencing to shut down your computer. Moreover, when shutting down the computer, you must do so in the standard manner. In addition to this, you should avoid installing malicious programs on your hard drive and keep on cleaning it regularly so that no unwanted programs remain there for long.

2. Computer Viruses & Malware

Computer viruses and malware infect the system and corrupt the system files that are stored on the hard drive. These viruses and malicious software usually enter the system from an outside source for instance, the internet and an external hard drive. These viruses first tend to attack the hard disk and then spread to other computers that are linked through the same network.

Keeping your computer’s operating system updated is one of the solutions for this problem. Moreover, another possible solution is installation and frequent updating of an antivirus software program. This antivirus is going to protect your system and your hard drive and make sure that it remains safe from their threat.

3. Manufacturing fault

Hard disks that haven’t been tested beforehand become unresponsive after a few months of use. This problem is encountered usually with new hard disks. The reason for this is more often than not a manufacturing fault which causes the hard disk to fail.

The best way to solve this problem is to be careful when purchasing a new hard disk. It is crucial to test the new hard disk before installing it in your computer system. However, if you have a hard disk with a manufacturing fault and it becomes unresponsive then the only solution available is to replace it.

4. Heat

Heating is a common problem associated with hard disks. If the system is overused, the fans of the hard disk start moving slowly and the system starts heating up immediately after being booted. Moreover, clicking noises can be heard from the hardware of the system too which is an indication that the hard disk is overheated. The reason for this is lack of proper ventilation or a faulty CPU fan which overheats the system to the point that the hard disk crashes.

The solution for the heating issue is to ensure that the CPU fan has been installed properly and is providing sufficient cooling to the hard disk. Moreover, you can install an application that keeps you notified about the temperature of your hard disk. If it starts exceeding the maximum limit then shut down the PC for a while and let it cool down before resuming your work.

5. Computer fails to detect hard disk or BIOS

The inability of the computer to detect the BIOS or the hard disk results from disturbances in the power supply provided by the UPS. This causes the hard disk to not spin properly which causes the PC to not detect either the BIOS or the hard disk.

The best possible way to solve this issue is to ensure that the power supply being used for the hardware components of the PC especially the hard disk are working properly. You can do this by changing the cable connecting the UPS to the hard disk and also by switching to a UPS of a reputable company.

6. Unexpected computer crashes

When the hard disk becomes too old it starts exhibiting all kinds of issues which can lead to unexpected computer crashes. The reason for this mostly is the accumulation of bad sectors over a large period of time. As the bad sectors pile up, the hard disk’s spindle motor malfunctions and read/write head becomes jammed. If this happens, you start hearing grinding noises from the hard disk and files and folders suddenly start disappearing.

You can solve this problem by properly maintaining your hard disk and installing anti-virus programs that keep your hard disk clean and protect it from the threat of viruses that can result in the creation of bad sectors. Moreover, replacing the hard disk after 3-4 years is also a good way to avoid this issue.

7. Human Errors:

Mistakes made by the user are also responsible for hard disk failures. For instance, improper installation of operating system, making changes to the settings of the system registry and changing the location of the system files are all human errors that can cause irreversible damage to the hard disk.

Avoid making any unnecessary changes to the system registry settings or altering the locations of the system files. Moreover, make sure that you are installing the operating system properly.

Hard disks are vital for the proper operation of a computer system. However, they are vulnerable to damage and problems which can cause them to lose the data that have been stored on them. However, by taking the necessary precautions, you can avoid the chances of hard disk failure.

The following are some tips that you need to remember if you don’t want to lose your precious data.

·  Install a good anti-virus program on your computer and regular update it.

·  Always create backups of your data in a separate location.

·  Never shut down your computer system while any program is running.