A+ Guide to Managing and Maintaining Your PC Fifth Edition Chapter 4 Electricity and Power Supplies

2 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Protecting Yourself Against Electricity Turn off power and unplug computer Always use a ground bracelet Never touch inside of a computer while it is turned on Never remove cover or put your hands inside monitor or power supply

3 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Static Electricity (or ESD) Can cause catastrophic failure or upset failure Protection against ESD  Ground bracelet / Ground mats  Static shielding bags

4 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Ground Bracelet

5 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Ground Bracelet with a Ground Mat

6 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Static Shielding Bags

7 A+ Guide to Managing and Maintaining Your PC, Fifth Edition EMI (Electromagnetic Interference) Caused by magnetic field produced as side effect when electricity flows Protection against EMI  Cover expansion slots  Do not place system close to high-powered electrical equipments

8 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Computer Power Supply

9 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Power Consumption Measured in watts, volt-amperes (VA), or kilovolt-amperes (kVA) The power consumption of a computer is mainly determined by  CPU: 60w – 100 w  Graphical card (3D): 60w – 70w  Hard drive  CD-RW/DVD  Motherboard: 20 (30)w

10 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Ventilation Forms an air flow that circulates (front to end, bottom to top)

11 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Power Management Energy Start (The Green Start) systems: satisfy certain energy-conserving standards of the U.S. Environmental Protection Agency Switches to different levels of sleep mode when not in use  BIOS  Operating System

12 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Power Management Setup Screen

13 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Changing Power Options

14 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Surge Protection and Battery Backup Surge suppressors – protect equipment from overvoltages on AC power lines Power conditioners – regulate the power, providing continuous voltage during brownouts Uninterruptible power supplies (UPSs) – provides backup power in a blackout to allow time for backing up important data

15 A+ Guide to Managing and Maintaining Your PC, Fifth Edition UPS

16 A+ Guide to Managing and Maintaining Your PC, Fifth Edition UPS Standby UPS (off-line)  powers equipment directly from the AC outlet. The batteries are used when the power fails, but with a small delay Line interactive UPS  provides a voltage boost on sags without accessing the batteries. On-line UPS  Conditions incoming power, and there is no delay to switch to battery.

17 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Purchasing a UPS Cost UPS rating (power support) Degree of line conditioning Warranty and service policies

18 A+ Guide to Managing and Maintaining Your PC, Fifth Edition The Computer Case and Form Factors Form factor describes size, shape, and general makeup of a hardware component Use same form factor for motherboard, case, and power supply  Decision driven by motherboard

19 A+ Guide to Managing and Maintaining Your PC, Fifth Edition ATX Motherboard

20 A+ Guide to Managing and Maintaining Your PC, Fifth Edition ATX vs. AT Form Factors Power connectors Soft switch vs. hard switch

21 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Power Connectors on AT and ATX Boards

22 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Other Form Factors NLX/LPX – uses a riser card Backplane – for rack-mounted systems

23 A+ Guide to Managing and Maintaining Your PC, Fifth Edition NLX Form Factor

24 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Troubleshooting the Power System Symptoms  The power supply fan is not spinning  The computer resets/stalls Troubleshooting by substituting

25 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Case Study Symptom  Whenever playing a game, the computer stalls

26 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Case Study Symptom  Whenever running a particular program for about two hours, the computer reboots

27 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Hands-on Projects Taking apart a computer and putting it back together Changing a power supply