Computer Display


Computer Display, Computer Monitor

  • Definitions
  • General Concepts
  1. Display resolution
    1. Monitor will have a maximum native resolution (width x height in pixels)
  2. Aspect ratio (Width to Height Ratio)
    1. Standard aspect ratio is 4:3
    2. High definition aspect ratio is 16:9 (previously 16:10)
  3. Refresh rate (RR=repaint/s) or Frame Rate (FR=next-frame/s)
    1. Most Computer Monitors are 60 refreshes/s (60 Hz)
    2. Contrast with some HD TV refresh rates of 120 Hz or 240 Hz (more appropriate for movies)
  4. Adapters
    1. See Wired Connections above
    2. Digital (HDMI, DVI) now, and previously analog (VGA)
  5. Configuration
    1. Install video card manufacturer's drivers (instead of default windows) and specific monitor drivers (if available)
    2. Settings (including multiple monitors) may be configured by right-clicking desktop (in Windows)
  • Types
  1. Liquid Crystal Display (LCD Display)
    1. Backlight
      1. LED (newer, better display of blacks) OR
      2. Fluorescent (older, entire lighting always on)
    2. Types
      1. Twisted Nematic (TN) - older technology, with narrow viewing angle, but faster response time
      2. In-Plane Switching (IPS) - more expensive, better color, better viewer angles, but may be slower response
      3. Organic LED (OLED) - very expensive, bright, but flexible material that could be rolled
  2. Projectors
    1. More powerful projectors have increased brightness (in lumens) and increased throw ratio (screen size)
    2. Configuration via on-screen display
    3. Bulbs are very expensive to replace
    4. Allow to cool off in stand-by mode with fan operational before turning off and unplugging
  3. Plasma Displays (ionized gas displays)
    1. Not typically for Computer Monitors (more for entertainment screens)
    2. Risk of burn-in with persistently displayed image (as with old CRT monitors)
    3. Image may be altered by radio interference
    4. Rich colors, strong blacks and good viewing angle
  • Differential Diagnosis
  • Display Problems
  1. Systems boots into VGA Mode (users may complain of oversized images and screen icons)
    1. Video driver issue (roll-back video driver, or uninstall and reinstall video driver)
    2. MsConfig settings incorrect (MsConfig allows setting video mode to VGA diagnostic mode)
  2. Screen remains black, blank on booting with no image shown
    1. Disconnected monitor cable (or monitor unplugged or off)
    2. Screen resolution mismatch with video card
    3. Computer may be in hibernation mode
    4. Monitor settings accidentally changed to expect different input
  3. Dead Pixels
    1. LCD or LED Display defect (typically covered by warranty)
  4. Screen artifacts
    1. Image problem
    2. Device driver issue
    3. Video card or other related hardware issue
  5. Incorrect color patterns
    1. Color profile issue (calibrate display)
  6. Image is dim
    1. Monitor screen brightness and contrast issue (adjust monitor controls)
    2. Video card or monitor driver settings issue (adjust driver settings)
  7. Flickering Image
    1. Interface or cable problem at the monitor or video card input
  8. Distorted image
    1. Video card and monitor resolution mismatch (typically video card selected resolution too high for monitor)
  9. Distorted screen geometry
    1. Monitor settings issue (adjust controls)
  10. Display "Burn-In"
    1. True burn-in does not occur with modern LCD panels (in contrast to plasma monitors and old CRT monitors)
    2. However, LCD panels may show image persistence with a prolonged image on screen
      1. Fully reversible, with various techniques
  11. Tools
    1. Startup files
      1. Reboot in safe mode into VGA (either via msconfig or with re-boot options as above)
    2. Device Manager (DevMgmt.msc)
      1. Check Display adapter (video card) properties and consider video card driver update or roll-back
      2. Check monitor properties
  • References
  1. Warner (2015) CompTIA A+, Pluralsight