This document provides guidance on diagnosing and troubleshooting computer system errors. It begins by outlining safety precautions like using anti-static devices and surge protectors. It then describes common computer system errors like no video output, failure to boot, and application crashes. The document classifies operating system errors and provides basic troubleshooting steps like checking cables and hardware settings, reviewing event logs, and taking notes. The overall goal is to plan preparation and determine the source of errors using manual and software diagnosis methods.

1. DIAGNOSE AND
TROUBLESHOOT
COMPUTER SYSTEMS (DT)
Prepared by
VICNENT B. ACAPEN

2. LO 1. PLAN AND PREPARE FOR
DIAGNOSIS OF COMPUTER SYSTEMS
ERRORS
• Follow OHS procedures in planning and preparing diagnosis of computer
systems errors
• Determine the computer systems errors using manual and software diagnosis

3. LESSON 1: PLAN AND PREPARE FOR
DIAGNOSIS OF COMPUTER SYSTEMS
ERRORS
• SAFETY PRECAUTIONS Personal Protective Equipment
Proper preparation is the key to a successful work. Before you begin, make
sure that you have the tools you will need, and secure a clear well-lit workplace.
Gather all the components you’ll be using and unpack them at the same time.
Always keep in mind that personal protection is one of the traits of a good
computer technician.

4. TYPES OF PERSONAL PROTECTIVE DEVICES
1. Anti-static devices
2. Power surge protectors
3. Personal equipment

5. ANTI-STATIC DEVICES
Devices designed to protect the computer from static electricity.
Source: www.desktopreality.com Anti-static Wrist Strap

6. Source: www.desktopreality.com Anti-static Mat

7. Source: www.desktopreality.com Anti-static Bag

8. Source: www.rapidonline.com Anti-static Spray

9. POWER SURGE PROTECTORS
Devices designed to protect the computer from sudden power surges from
intermittent power sources.
Examples:
1. AVR (Automatic Voltage Regulator)
Source: www.neopower.com

10. 2. UPS (Uninterrupted Power Supply)
Source: www.amazon.co.uk

11. PERSONAL EQUIPMENT
1. small paint brush
2. screw drivers

12. 3. pliers and tweezers
4. compressed air

13. 5. handheld vacuum

14. TYPES OF COMPUTER SYSTEM
ERROR
• 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.

15. 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.

16. 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.

17. 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.
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.

18. BASIC TROUBLESHOOTING.
1. 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.
2. 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.
3. 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.
4. Notice changes: When you notice a software or hardware error in your computer,
determine what was changed before the problem occurred.
5. Event viewer: In the event viewer, you will find the error or warning messages associated
with any faulty hardware or software.
6. 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.