Troubleshooting PC

1
Chapter 11

• Troubleshooting PC
• Hardware

2
Troubleshooting Basics

• Effective troubleshooting uses techniques to
  diagnose and fix computer problems. A series of
  logical steps speeds up the troubleshooting
  process.

3
Troubleshooting Tools and Aids

• Every technician should have a good toolset.
• The typical toolset will include items such as 
• Flat-head screwdriver
• Phillips-head screwdriver
• Nut drivers
• Needle-nose pliers
• Diagonals or crosscut pliers
• Mirror - helps see into very tight spots
• Flashlight

4
Troubleshooting Tools and Aids

• The toolset should include a digital multimeter,
  which is a measuring device.
• A digital multimeter can measure voltage, amps,
  and ohms in both alternating and direct current.
• A digital multimeter can be used to test power
  supplies, DC/AC voltage and polarity, resistance
  (Ohms), diodes, continuity, coaxial cable, fuses,
  and batteries.

5
Troubleshooting Tools and Aids(Digital
Multimeter)
6
Troubleshooting Tools and Aids

• Loop-back plugs can provide important diagnostic
  information while troubleshooting serial and
  parallel ports (printers).
• Loop-back testing works by sending signals out
  and verifying if the correct input is received
  back.
• Diagnostic information can be gained from
  individual pins, ports, controllers, and printer
  output.

7
Field Replaceable Units

• Devices that can be replaced or added in the
  field are called Field Replaceable Units (FRU).
  FRUs do not require any soldering and are easy to
  remove and install.
• Common FRUs are
• Monitors lPower Supply
• Keyboard/ mouse lRAM DIMMs, SIMMs, RIMMs, etc.
  
• Modular expansion cards lFloppy and fixed disk
  drives
• Most microprocessors lMotherboard

8
Input Devices

• Input devices such as a keyboard, mouse,
  scanners, and digital cameras transfer data into
  the computer. Most input devices are detected at
  startup.
• When troubleshooting input devices, always start
  with the simple solutions. Check to make sure the
  device is properly connected.
• After checking the physical connections of the
  input device, try rebooting the computer.
• Pay attention to any errors that display during
  startup.
• The errors will be indicated either as a text
  error on the video display or a POST beep code (a
  keyboard is not properly connected, the user
  might get a beep code or a "301 error message.)

9
SCSI Interface Issues

• SCSI drives require a separate controller from
  the IDE controller.
• The SCSI bus operation and the transfer rate are
  controlled by adapter settings. If there is a
  transfer speed mismatch amongst the SCSI
  controllers, the drive might have I/O errors.
• As a rule, attach the SCSI controller set to the
  last SCSI ID, which is SCSI ID 7. Input/Output
  errors might result if the SCSI ID is not set to
  7.
• An important consideration with SCSI IDs is, the
  higher the SCSI ID, the higher the priority. The
  actual ID priority is 7, 6, 5, 4, 3, 2, 1, 0, 15,
  14, 13, 12, 11, 10, 9, 8.