Copyright © 2007 Heathkit Company, Inc. All Rights Reserved PC Fundamentals Presentation 4 – Inside the Computer

2 Objectives At the end of this presentation, you will be able to:

3 Discuss precautions that you should take before and during the disassembly of a computer. Discuss Electrostatic Discharge (ESD) and ways that it can be avoided. Identify, disconnect, and reconnect the computer’s cables and cover. Identify the external connectors on a typical personal computer. Identify and explain the purpose of the power supply. Identify the connectors on both the ATX and the older AT type power supplies.

4 Why Disassemble the Computer? To upgrade. To repair. To add to it.

5 The three most important things to remember when disassembling a computer are: Document Document!

6 Document Where cards are located. How cables are routed. Orientation of cables and connectors. Hardware used to secure each component. Anything else that might cause confusion when reassembling.

Your greatest enemy when working inside the computer is Electrostatic Discharge or ESD.

8 Your best defense against ESD is the anti-static wrist strap.

9 An internal resistor provides shock protection. 9

10 Switch off power at the computer and at the workbench...

11...but leave the computer plugged in.

12 Use anti-static mats on the workbench and floor.

13 Hold Circuit Boards by their Edges.

14 Store Circuit Boards in Anti- static Bags.

Tips for Disassembly.

Turn off power to the computer and everything connected to it.

17 Before Disconnecting the External Components Keyboard Mouse Monitor Parallel Port

Disconnect the monitor and set it aside.

PS/2 Keyboard Connection Disconnect the keyboard and set it aside.

20 DIN Plug Keyboard Connection

PS/2 Mouse Connection Disconnect the mouse and set it aside.

22

Removing the side panel.

24 Remove these screws...

25... not these.

Spreading the sides of the cover will help it to clear the computer.

28

29 The Motherboard.

30 The Motherboard may also be known as the: System Board Planar Board Baseboard Main Board Logic Board

31 The Power Supply.

32 Standard Power Supply

33 Power Selection Switch

34WARNING! Hazardous voltages contained within this power supply, not user serviceable. Do not repair.

35 Power Supply Connectors

36 Power Supply Output Voltages ATX-Type +5 Volts +12 Volts -12 Volts -5 Volts +3.3 Volts

37 ATX 20-pin Power Connector

38 20-Pin ATX Power Connector

39 24-Pin ATX Power Connector Pin 1 Pin 24

40 2 X 10 ATX Connector 2 X 2 Connector

41 A Second 2 X 2 Motherboard Power Connector Supplies Processor Core Power (+12 Volts)

42 Power Supply Output Voltages AT-Type +5 Volts +12 Volts -12 Volts -5 Volts

43 Motherboard Power Connectors Black Wires Black Wires P9 P8

Large Molex Connector

Berg Connector

Some connectors are held in place with a latch.

47 Grasp the connector by the shell… Never by the leads.

Copyright © 2007 Heathkit Company, Inc. All Rights Reserved PC Fundamentals End