Troubleshooting Video and Display Issues – CompTIA A+ 220-1101 – 5.4

Display problems can bring all work to a grinding halt. In this video, you’ll learn how to troubleshoot bad displays, image quality issues, LCD projectors, and much more.

If you see no signal from a video display then it’s possible that you have the cable that has become disconnected, or perhaps a cable has been damaged. If you check the connectivity and reseat the cables, it’s possible that the issue would be resolved. Many monitors also have video input selectors, especially monitors that have multiple interfaces for input. So you can use that input button to choose the HDMI, DisplayPort DVI, or whatever interface you happen to be using as input to that monitor.

If you look closely at the display and you notice there is a very dim image, then it may be that the brightness or contrast needs to be turned up on the display. There are often buttons on the display itself that allow you to customize those settings. And ultimately, it may be that the monitor has simply failed, and replacing it with one from a known good system can tell you whether the issue is with the monitor or with something outside of the monitor’s configuration.

If you’re getting a black screen when you start the Windows operating system, you may want to choose the option for VGA mode, which you can access by pressing F8 during the Windows start up process. This will start Windows in a very basic resolution that should be compatible with most monitors on the market.

Instead of having a completely black display, you may be able to see some information on the screen. But there could be flickering or color issues. You may want to check the cable itself and make sure that none of it has been damaged. And if you’re using VGA, you might want to check the individual pins of the video connection itself.

If the display is distorted, or the geometry of the display seems off, you may check the configuration settings in the operating system. The driver may allow you to change refresh rates or resolution settings to something that’s more compatible for that monitor.

If you’re not sure what this should be, then you should check the documentation for the monitor, which will tell you exactly what resolutions and what refresh rates are supported by that device. And if your video adapter supports hardware acceleration, you may want to try disabling that temporarily to see if that resolves some of these display issues.

One challenge when working with LCD displays is that there are a fixed number of pixels on that display. You don’t have a way to modify the resolution of that display since those pixels are fixed in place. That means that you need to use display settings that match the physical configuration of that display. And if you can match the native resolution of that display, you will have the sharpest picture available on that output.

If you don’t match the resolution, you might have an output like this one that shows some letters as being larger and more blocky than other letters in the output. This usually indicates that the wrong resolution is being used, and we might want to change our resolution to better match the capabilities of the monitor.

If you don’t want to use the native resolution of the display, then use one that is a factor that is compatible with that native resolution. For example, if the native resolution was 2560 by 1600, you could use the resolution of 1920 by 1200 because that is exactly the same ratio in both of those resolutions.

A problem that can occur across all display types is the problem of “burn-in.” This is when you have a single image on the screen that stays for a very long time and it stays for so long that when you remove that image from the screen that a portion or ghost of that image is left on the display.

Some displays have a technology known as “pixel-shift” built into the display to help prevent this. It will slightly move an image that is not changed after a certain amount of time by just a pixel or two in an effort to prevent this type of burn-in. It’s such a slight change to the display that you’ll probably not even realize that the display is moving, especially if you have a single image on the screen for an extended period.

On LCDs you may see this burn-in referred to as “image sticking,” and one way to clean the screen from the stuck image is to display a white screen for an extended period of time. You’re effectively trying to reset this image so that it is no longer stuck to our LCD.

Here’s a closer view of the burn-in on a display that’s in an airport. You could see the list of all of these airlines and flights, and you can see that in the past there was some text that was off to the side that said “on time.” Now that’s been moved to the left just a little bit. And you could see the primary text in the foreground and the burned-in text in the background.

Some LCDs have one or more pixels on the display that simply don’t have any color on them at all. They are completely black and they always stay black. We refer to these as “dead pixels” because they never show any other type of color other than black. This is not something you can really resolve on the user side. And there’s no way to go into the monitor and somehow enable that one pixel.

This is not a cable issue. You can’t provide any other type of power source. That pixel will stay black, and there’s really nothing you can change with the monitor or the cabling that will resolve that. Before swapping out the display or making any change to the hardware, you might want to make sure that what you’re seeing is on the display itself and not something on the outside of that display.

So before you remove this monitor, it might make sense to clean the monitor to make sure that the dead pixel you’re seeing is not something that is attached to the display itself. And with a dead pixel, there’s really no way to bring that pixel back to life. If you would like to have a display without dead pixels, then you will need to completely replace this LCD.

Here’s a closer view of this dead pixel. You can see that it is this black pixel on the right side. This could be something very obvious if it’s in a portion of the screen that you happen to use a lot. And of, course, if you’d like to fix that dead pixel, you’ll need to replace the entire display.

There may be some cases where you’re using your monitor and everything is working normally, and then, suddenly, there’s a flickering of the image. It’s suddenly there and then not there and then suddenly back again. This is often caused by a loose cable. So you can reseat the cables or replace it with a new cable and you’ll no longer have the flickering issue.

Replacing the cable is a very quick fix and it often resolves this issue. But if the problem is with the monitor itself, then you’ll need to replace the entire display to resolve this flickering. Before swapping out any hardware, though, you may want to check the configuration of the monitor and make sure it matches the settings with your video driver. If there’s a difference between the capabilities of the monitor and what you’re sending to that monitor through the driver, then you may get flickering with the output.

Another challenging troubleshooting task is when the output that is shown is the wrong color. There might be one particular color that’s shown more than another, or the whole mix of colors on the screen may be incorrect. You first might want to look at the configuration of the monitor, specifically, the tint or any custom color presets. And if you can’t find any problem with those, it might be worthwhile to perform a factory reset of the monitor’s configuration.

If everything looks OK with the monitor, you might want to check the configuration inside the driver of the operating system. There may be settings in there that allow you to adjust the tinting or any special settings that might change the colors on the screen. And lastly, you might want to check the operating system to see if it modifies colors depending on what time of day it is.

Some operating systems will decrease the amount of blue color that’s used during the nighttime hours because they feel that the blue color can affect your sleep patterns. Your operating system will probably have a nightlight or evening settings and you can choose to enable or disable that capability.

Because this is a video about troubleshooting display problems, we should also talk about audio issues associated with those displays. Many of us use the speakers that are built into our monitor, so if we’re having some type of audio problem, we need to adjust our display to resolve that problem. There may be controls for the audio on the monitor itself. And you may be able to increase or decrease the volume on the front panel of the monitor.

It’s also important to know what’s feeding that audio to the monitor itself. Is this a separate audio cable, or is the audio integrated into the HDMI connection? Your monitor has a configuration setting that allows you to choose which audio input is used for the speakers that are built into the monitor. And, depending on the capabilities of the display, there may be many different audio inputs. These might be analog or digital, or they might be integrated into the video signal itself.

If the display on the monitor is very dim, then you may want to check the brightness and the contrast settings. They’re usually configurations on the monitor that allow you to modify what these values are, and you can adjust them to match the lighting of your work area. Some operating systems will automatically dim the screen, depending on the time of day. And they might dim it based on how much power you have in the battery of your laptop. These configurations can usually be modified in the driver settings or in a separate display configuration application.

If the display seems to be black, but if you look closely you can almost see the display being shown, then you might have a backlight failure. There’s a backlight on our LCD that shines a light through the display so that we’re able to see the information on the screen. If that backlight fails, it will be very difficult to make out anything that’s being displayed. Some monitors allow you to replace the backlight that’s on the display, or you may have to replace the entire display to resolve this issue.

If you’re working in a conference room, you may be using an LCD projector like the one you see here to display information on a screen. You commonly see these used in environments where you need to have a lot of people viewing the information that’s on one single screen. We often refer to these devices as “LCD projectors,” but there may be other technologies that are used inside the device itself. However, as a generic term we often refer to these as an LCD projector, even though they might be using some other type of technology.

Inside of these projectors is a very bright lamp. That’s what allows everyone in the room to be able to see the information that’s being shown on the wall. The light that we have on the inside is a metal halide lamp, which is a very bright lamp that allows everyone to see the output that’s being shown on the wall. Because it’s a very bright light, it tends to also be a very hot light.

These lamps can also be expensive to replace, with the cost going up as high as $350 to replace one lamp inside of these devices. For this reason, a best practice is to always leave the fan running when you turn off one of these LCD projectors. This allows the lamp to cool down slowly and hopefully extends the lifetime of that individual lamp.

If you’ve already replaced the lamp and you notice that the projector intermittently shuts down, goes completely black, but the fan continues to run, then you may have a situation where there’s a cooling problem. You may want to check the cooling vents on the LCD projector and make sure that the fan inside is blowing air through the entire system. If there’s any problem with that cooling process, then the sensors inside of the LCD projector will recognize that it’s getting too hot and it will automatically turn off to prevent any additional damage.

So if you have a way to remove any blockages or clean out any of the dust that may be on the outside of this projector, it will improve the overall airflow. Some projectors also have air filters built into them and you may need to replace those filters to have a better airflow through the system.