Troubleshooting Computer Systems

Tools for Testing Computer Systems

• Tools and equipment are important for troubleshooting, helping users identify errors in computer hardware and networks.

Tools for Testing Hardware Problems

• Screwdrivers install and remove screws.
• Pliers and tweezers pick up small parts.
• Soldering irons connect terminals in power supplies and circuit boards using soldering lead.
• Anti-static wrist straps, mats, and sprays eliminate electrostatic discharge.
• Lens cleaners clean optical media like DVD-ROMs and CD writers.
• Thermal paste dissipates heat from the processor.

Network Troubleshooting Tools

• LAN testers test network connections.
• Crimping tools crimp RJ45 connectors to UTP cables.

Causes of Network Trouble

• Networks may fail if a network card isn't properly connected, drivers/software settings are faulty.
• A network may fail due to firewall restrictions, connection problems, or bad network hardware.

Network Trouble Solutions

• Due to varied network configurations, the following recommendations may not apply to all systems.
• If issues persist after troubleshooting, contact the network administrator or company representative.
• Verify network cable connections at the back of the computer and check the LEDs for proper illumination.
• A solid green LED indicates the card is either connected or receiving a signal.
• Ensure a new network card's resources are properly set without conflicting with other hardware.
• Verify the network card's ability to detect itself using the ping command in Windows/MS-DOS prompts.
• Unix/Linux variant OS users perform ping via the shell.
• Verify the correct protocols are installed.
• Most networks use TCP/IP, but may also use IPX/SPX and NetBEUI.
• The user must specify an IP address and subnet mask when the TCP/IP protocol is installed, if a DNS server or other computer does not assign the IPX address.
• Ensure all necessary ports are open if your network uses a firewall; if possible, disable the firewall software or disconnect the computer to rule out firewall issues.
• It can take a computer 2-3 minutes to connect or detect the network after booting.
• If problems persist after following recommendations, with TCP/IP, ping another computer's IP address to check if the computer can send/receive data.

Computer System and Network Configurations

• Computer networks connect computers, software, and hardware, enabling users to collaborate.
• Cabling systems, specialized software, and devices manage data traffic on a network.
• Users can share files and resources like printers, and send messages electronically.
• Designing a network plan can take 1-3 working days, based on network size and assistance available.

Making Cabling

• Remove 12mm of the outermost vinyl shield from one end of the cable (A-side).
• Arrange metal wires in parallel according to the wire arrangement table without removing the shield of each metal line.
• Insert the metal wires into the RJ45 connector, keeping the metal wire arrangement.
• Use pliers to set and squeeze the RJ45 connector with the cable tightly.
• Repeat these steps on the other end of the cable (B-side).
• The cable can be set at either end of the device.

10 Base T / 100 Base T Straight-through

• 10BaseT and 100BaseT are common LAN modes using UTP category-5 cable.
• A UTP category-3 cable can be used for 10BaseT, which contains 3 wires.
• The pin configuration is:
  • Pin 1: white-orange to white-orange
  • Pin 2: orange to orange
  • Pin 3: white-green to white-green
  • Pin 4: blue to blue
  • Pin 5: white-blue to white-blue
  • Pin 6: green to green
  • Pin 7: white-brown to white-brown
  • Pin 8: brown to brown
• A straight cable connects a computer to a hub or two hubs through an uplink port.

10 Base T / 100 Base T Crossover

• Cross cables for 10BaseT and 100BaseT connect two computer directly using only a UTP cable.
• It is also used for connecting 2 hubs with a normal port on both hubs, a relatively rare configuration.
• The pin configuration is:
  • Pin 1: white-orange to white-green
  • Pin 2: orange to green
  • Pin 3: white-green to white-orange
  • Pin 4: blue to blue
  • Pin 5: white-blue to white-blue
  • Pin 6: green to orange
  • Pin 7: white-brown to white-brown
  • Pin 8: brown to brown

Inspecting and Testing Configured Computer Systems and Networks

• Practice good housekeeping during and after machine maintenance.
• Place removed parts in safe locations away from personnel during servicing.

Electrical Safety

• Electric current from power, telephone, and communication cables can be a hazard.
• Disconnect power cords, telecommunications systems, networks, and modems before removing server/workstation covers unless specifically instructed otherwise.
• Disconnect power before performing mechanical inspections, working near power supplies, or removing/installing the main unit.
• To avoid risk of electrocution, unplug the machine's power cord before beginning work.
• Never assume a circuit is de-energized; always verify that the power has been switched off first.
• Be vigilant for possible hazards, such as moist floors, non-grounded power extension cables, and power surges.
• In the event of an electrical accident, turn off the power and send for medical assistance.

Accident Reporting Policy and Procedure

• Implement a process for reporting accidents and incidents for quick action and tracking causes.
• The organization should define what, to whom, and how to report, and document the process.
• These are the defined rules and guidelines to ensure proper documentation, reporting, and investigation of all accidents and injuries.
• Designed to promote safety, prevent future incidents, and comply with legal, organizational mandates.
• The aim is to ensure that all accidents, injuries, and near-miss incidents are correctly reported and investigated.
• All employees, students, or visitors involved in/witnessing an accident must report it.
• Report workplace injuries, accidents involving equipment, fires, electrical incidents, or chemical spills.
• Report accidents to a teacher, supervisor, or safety officer immediately.
• All accident reports are kept confidential to protect the privacy of those involved.

Accident Investigation Procedures

• Prioritize safety and call for medical help if someone is hurt.
• Remove immediate hazards to prevent further accidents.
• Report the Accident Immediately to the teacher, supervisor, or safety officer.
• Document injured person's name, date/time, injury type, first aid, and actions taken to avoid future accidents.
• Submit the report to the appropriate person/department, such as the school administrator or principal.
• A safety officer or administrator analyzes the report to find the accident's cause through interviews, equipment checks, and policy reviews.
• Execute corrective actions based on the investigation, by repairing faulty equipment, enhance safety measures, and provide extra training.
• Supervisors/teachers should follow up with the injured person to check they are recovering well and safety inspections should also be conducted to prevent further accidents.