OS-related symptoms:

These are symptoms or behaviors that are generated by the OS; while they may be caused by hardware in some cases, techs need to address them at the OS level first.

        Blue screen of death (BSOD):

A BSOD is caused when a kernel mode process, meaning the process has full access to all system resources, is corrupted or is unable to continue, causing Windows to do a complete halt. When the BSOD appears, it will have an error code and message telling the general reason for the process shutdown; this can be looked up to get more information. BSODs can be generated for a number of reasons, but they’re commonly caused by defective or incompatible hardware, drivers or software; registry issues; and viruses and malware. A restart will clear the BSOD, but unless the underlying cause is addressed, it will likely reoccur.

         System lockup:

This is when a computer locks up or freezes. Usually no error messages like blue screen of death. Can be caused by: hardware/driver issues with the motherboard, video card or memory; configuration issues in the BIOS, most often with RAM; or even CPU issues.To find the problem, ou can use the Event Viewer to narrow down causes. You can also use other tools like Windows Memory Diagnostics or DxDiag.

            I/O device:

Issues with I/O can be unsual behaivor, sucha s hesitation or jerky movement of the cursor, static when typing or mocing the cursor; or simple failure to work at all. Device conflicts can be easily seen in the Device manager, where a yellow exclamation mark icon may indicate a device conflict, or the device may not be listed at all.

       Application install:

Sometimes, when you install something the installation won't finish or it stops after generating an error message. There is normally an error message if an installation goes wrong, but if not, the most common errors are due to: 

- a lack of space on the hard drive being installed to (usually the root drive, C:);

- the computer not meeting minimum requirements for the application, usually RAM or CPU speed;

- the root folder for the install not having sufficient space, which is more of an issue for systems running on an older File Allocation Table (FAT) system;

      Start or load issues:

Some applications will not open or will be unable to complete the load process after being installed. When this happens, it may not show an error message. The application may simply not appear, or the process may show up in task manager, but not in the UI. 

In these cases, issues preventing the application from loading can include: 

- incompatibility with the hardware   - invalid directory

- a missing/damaged shortcut    - system configuration

- operating system

- application components improperly listed in the system registry.

             Windows-specific

         printing problems:

Technicians may occasionally run across printing issues where a test page can be generated from the printer successfully, but Windows can’t print to the device.

After eliminating hardware issues, such as a bad or loose cable, two of the more common Windows printing issues involve the printer not printing at all because of the print spooler stalling (a service in Windows that may need to be stopped and restarted) or, if the printer prints pages of incomprehensible characters, a corrupted, incompatible or incorrect printer driver, which can be removed in Device Manager or updated through either Windows Update or the printer manufacturer’s update tool.

Hardware-related symptoms:

Errors or performance issues on a computer may be due to the hardware itself failing or malfunctioning. Some of the common symptoms and signs of hardware issues include:

Excessive heat

Noise

Odors

Status light indicators

Alerts

Visible damage

         Excessive Heat:

The cpu, chipset, motherboard, and RAM, as well as other chips inside a computer are all extremely sensitive to heat. Too much heat will cause a computer to behave erratically, lock up, shut down at random intervals or refuse to come on at all.

The first place to look are the various fans in the system

Dirt and dust can cause fans to slow down or fail altogether, or prevent air movement if there are too many clogged vents or dust bunnies.

                  Noise:

Different computers make different kinds of sounds accordingly, but if th user notices a change in voume or pitch, it may be a sign of hardware issues.

Less noise may mean a fan slowed or stopped working.

If a fan gets louder it may be a sign it’s become gummed up with dust and dirt, and is not working as efficiently or smoothly.

A hard drive also makes noises when running, but if a drive makes a high-pitched noise or starts to click and thump, those are frequently signs of imminent problems.

                Odors:

Odors coming from a computer generally indicate either a spill of some kind or a potential electrical issue

spill, while not necessarily damaging, should be cleaned up right away, and the system should be checked carefully to ensure no electrical damage was caused.

    Status light indicators:

Some devices, like NICs and some laptop batteries, have light-emitting diode (LED) status indicators built into them. These status indicators can indicate if network traffic is getting through, in the case of NICs, or the charge level for laptop batteries.

Status indicators should be checked to see if an issue is indicated.

                 Alerts:

Alerts are tasks in Windows set to go off when a certain condition is met, such as low battery power.

While not error messages themselves, they can point to hardware issues if alerts are appearing far more frequently than they should.

        Visible damage:

One of the things that techs should immediately look for if an unusual odor is detected is visible damage.

Such damage includes:

- stripped or burned cables

- cracks in cases

- smoke and melted plastic

Visible damage should always be checked after an electrical event or impact to a system, even if the system works fine immediately afterward

              User documentation

                  and resources:

When researching symptoms and possible solutions, there are certain resources that a technician should start with, particularly if working on a system or technology that’s unfamiliar.

These resources include:

User/installation manuals

Internet/Web-based resources

Training materials