Troubleshooting Video, Projector & Display Issues | CompTIA A+ 220-1001 | 5.4

In this video you will learn about common symptoms associated with video, projector & display issues.

VGA Mode

A Windows computer will start in VGA mode if Low-resolution mode or Safe mode has been selected at startup or if the correct drivers are not available. 

VGA Mode or Low-Resolution Mode

Check the following if this occurs:

  • Make sure correct chipset drivers for the motherboard/system drivers have been installed.
  • If using a separate video card, be sure to install the new drivers after the card is installed.
  • If the system is being upgraded by replaced with a new video card with a different manufacturer’s chipset, uninstall the current video card drivers and support apps from Device Manager & Programs and Features.

No Image on Screen

Having no image on the screen can be due to a variety of different reason according to the computer & display type.

Overheat Shutdown

To avoid overheating shutdowns with projectors, check the following:

  • Clean or replace filters when recommended by the manufacturer or the actual projector itself.
  • Ensure that the projector has adequate ventilation.
  • Clean air intakes & exhaust ports for dust/dirt.
  • To reduce heat, use lower brightness settings.
  • Allow for the projector to completely cool down before disconnecting it from power.

Dead Pixels

A dead pixel (or a defective pixel or a black pixel) is a pixel on an LCD that is not functioning properly. Dead pixels usually result from manufacturing defects in an LCD screen.  Some “dead” pixels are actually stuck on (bright) or off (dark). Due to the relatively cheap prices of displays, the easiest fix for resolving a dead pixel problem is to simply replace the LCD display.

Dead Pixel


Artifacts (more commonly known as digital artifacts) are errors (distorted shapes, colors, pixelated images, scrambled text, or lines through an image) that occur during signal transmission or interpretation. Artifacts can be caused by an overheated GPU or projector, overclocked GPU, overcompressed grahics, overcompressed video, & low-resolution video or image that has been enlarged to a higher-resolution display.

Video Display Artifacts

To solve overheating problems with a GPU:

  • Check the card’s cooling fan.
  • Check the CPU heat sink/fan with CPU-integrtated video.
  • Disable overclocking and return the card/system to normal clock speeds.

Incorrect Color Patterns

To fix incorrect color patterns on a projector, try the following:

  • Make sure you have the correct signal type in the projector menu.
  • Replace any failing LCD panels in an LCD projector.
  • Clean the projector LCD panels if odd-colored specks are visible.
  • Check to make sure that the LCD ribbon connector connected to the computer’s motherboard has not been damaged.
  • Check to make sure that there are no damaged or loose video cables/connectors.

Dim Image

Incorrect settings or equipment failure can result in a dim image. Check the following:

  • Check the screen brightness controls.
  • Check the settings of a display management program that is being utilized.
  • Check the built-in screen brightness settings on a mobile device.
  • Check the projector bulb on a projector to see if it is not shining as bright indicating that it may be time to replace the bulb.
  • Check the inverter on a device that uses a CCFL backlight.  Failing inverters can cause a dim display.

Flickering Image

A flickering image can have many causes:

  • Try updating the GPU or chipset drivers before tinkering with the hardware.
  • Failing inverters can cause flickering on displays using an LCD-CCFL backlight.  If the actual backlight is failing on an LCD, replace the entire display.
  • Check to make sure all cables and connectors are secure. If using a two-in-one convertible device (tablet/laptop), check to make sure there isn’t any issues with the hinge.
  • Check PCIe card power connectors & the power supply on desktop computers.  If the problem happens after the computer has been running for a while, it could indicate a heat-related problem.

Distorted Image

Distorted images can be caused by several reasons, including the following:

  • Change video drivers if image tearing or distortion occurs in 3D games.  Check driver versions with Device Manager’s properties sheet or the proprietary app installed by your GPU or video card maker.
  • DisplayPort connections can present problems of distortion with the way some DisplayPort cables and connectors are manufactured.  Try using a different connection (DVI or HDMI) between the system and a display. If the problem is still there, replace the DisplayPort cable.
Distorted Video Image

Distorted Geometry

Distorted geometry is common with CRT displays but not with LCD or LED displays.  However, other factors can cause issues:

  • Keystoning: If a projector lens is tilted or downward toward the screen, non-parallel sides on the projected image is the result.  Most projectors have keystone correction options.
  • If a projector is not at a 90-degree angle to the projection screen, the image will be larger on one side than the other.  Some projectors have adjustments for this problem.  If a projector does not have that option, adjust the projector or screen position until the image is the same size across the screen.
  • Parts of the picture coming from a projector might be out of focus if the projector is tilted or is not at a 90-degree angle to the screen.
  • Curved screen HDTVs have subtle geometric distortions that increase at greater off-axis viewing angles.  Place seating closer to the middle of the display.


Screen burn-in (also known as ghosting) is a discoloration of areas on an electronic display such as a CRT (cathode ray tube) display or an old computer monitor or television set caused by cumulative non-uniform use of the pixels. Burn-in can also affect LCDs and plasma displays.

LCD Burn-In

Oversized Images & Icons

Booting a computer in Limited-resolution (VGA) mode can cause oversized images and icons in Windows.  The menus and icons are rather enormous and as a result, many apps cannot be used at this resolution.  To fix, restart the system and select resolutions form the Display properties sheet in the Control Panel. Now understand that there are options in Windows to purposely make the icons very big.

Oversized Images & Icons