PC Maintenance Preparing for A Certification Chapter 17

PC Maintenance: Preparing for A+ Certification Chapter 17: Keyboards and Mice

Chapter 17 Objectives Understand keyboard and mouse functionality n Identify types of keyboards and mice n Connect and disconnect keyboards and mice n Troubleshoot common problems with keyboards and mice n

How Keyboards Work Grid of uncompleted circuits n Pressing a key completes the circuit n Each key sends a different signal n Modifier keys (Shift, Ctrl) change the signal that is sent by another key n

Keyboard Layouts n XT Keyboard, function keys at left, no separate arrow pad

Keyboard Layouts n Windows Keyboard, has function keys on top, Windows keys, separate arrow keys

Keyboard Layouts n Dvorak keyboard, different arrangement of keys, requires user retraining, faster typing (by some claims)

Keyboard Connectors AT-style (older, larger) n PS/2 -style (newer, smaller) n USB (newest) n

Standard Ball Mouse Ball rolls past sensors that send electrical pulses to PC n Ball removable for cleaning n

Optical Mouse Light sensor instead of ball n Sealed case, no cleaning required n Lasts longer than a traditional mouse (in theory) n

Mouse Variants Trackball n Touchpad n Light pen n

Connecting/Disconnecting USB models can be connected without shutting down PC n PS/2 mouse can be connected without powering down if Windows fails to detect a mouse at startup n All other connections/disconnections must be done with power off n

Adjusting Keyboard in Windows Keyboard properties in Control Panel n Repeat Delay n Repeat Rate n Cursor Blink Rate n

Adjusting Mouse in Windows n Buttons: Swap right and left n Double-click speed n Pointer Appearance n Pointer Movement n

Troubleshoot Keyboard Problems n Keyboard not detected Check connection n Bad keyboard n n Stuck key message at startup Object resting on keyboard n Dirt or object wedged into keys n n Nonresponsive key n Clean keyboard

Troubleshooting Keyboard Problems n Wrong letters appear when typing Check keyboard layout chosen in Windows n Remove keyboard from Device Manager and redetect n Bad keyboard (faulty controller chip inside) n n Spilled liquid on keyboard If sugared liquid, clean with soap and water n Let dry completely n Replacement might be necessary n

Troubleshooting Mouse Problems n Pointer does not move at all Mouse disconnected n Windows locked up (reboot) n Bad mouse n n Pointer moves in only one direction Mouse requires cleaning n Roller inside is malfunctioning (clean, replace entire mouse) n

Troubleshooting Mouse Problems n Pointer jumps erratically all over screen Dirty mouse n Bad or incompatible video driver n Check in Safe Mode to eliminate driver as possibility n n Extra buttons do not work n n Software for mouse not installed Touchpad does not click when tapping n Software or driver not installed