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