Troubleshooting Video and Display Issues – CompTIA A+ 220-802: 4.4

| May 27, 2013

Most of us have one (or more) video displays connected to our PC. In this video, you’ll learn to troubleshoot blank screens, image quality problems, and other video issues.

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To be able to use our computers, we need some type of visual feedback. So in this video, we’ll look at troubleshooting video problems that you might run into. If we’re not seeing anything on the screen, we may want to first check to see if things are plugged in properly. It seems like such a simple type of problem, and occasionally people can be offended that you’re even asking them if it’s plugged in. The problem is that things sometimes don’t get plugged in properly, so having a double check on both power and the video data cable itself will be a good sanity check before moving on.

Our monitors these days can plug into so many types of video connections. It might be an HDMI connection. It might be an old school VGA connection. I might use DVI as the video signal. But the monitors generally don’t automatically determine where the signal is coming from. You have to tell the monitor what’s plugged in, and if you haven’t configured that properly, you’re obviously not going to see anything on the screen. There’s usually a button on the monitor somewhere that allows you to choose from the correct input. So make sure that the input that you’re bringing from your computer matches the configuration of that monitor.

If the monitor is getting a signal but it’s very, very dark or hard to see anything, then maybe it’s simply the brightness display. You can use the brightness controls on the monitor to turn the brightness up so that you’re able to get that back light shining through so that you can see exactly what’s being displayed on the monitor. Sometimes, you’re just not sure if the monitor itself is working or not, so it may be useful to grab that monitor, move it over to another computer, plug it in there, and see if you get the same symptoms. That way, you’re able to at least make a determination that the problem might be in that monitor itself.

If you started your computer, you see your power on self test messages go by, you see the Windows splash screen starts up, and then everything goes black but you can still see the computer is working, then the problem may be with the video settings that are inside of Windows. Well, here’s the catch-22, of course, is that you can’t now change those configuration settings inside of Windows because you can’t see what’s on the screen.

Fortunately, Windows gives us a workaround that we can use to fix this. We can restart our systems and before Windows has a chance to start, we can press the F8 key to get our System Startup Options, and inside of there will be a low resolution mode or a VGA mode that will start up the Windows operating system in a very low resolution that should work on any monitor.

Maybe the problem isn’t that the screen is black but that the quality of the picture itself is very bad. Maybe it’s very blurry, maybe we’re missing colors, maybe the screen is flickering. There’s a number of things that we can look at to help resolve these issues. Make sure you check the pins on the connectors you’re using. If you’re using a VGA connection, it’s very easy to bend those pins when you’re plugging it into the VGA port, and just by bending one pin can remove an entire color from the screen. So if suddenly the screen is very green or very blue, you might want to check the end of that connector and make sure that you didn’t crush any of those pins trying to put it in. So use a screwdriver or something very small to bend that pin back into the right position and try plugging it into the computer again.

If we’re seeing flickering or the screen is not working the way it should, then perhaps we have a mismatch between the settings that are in our Windows configuration and the settings on the monitor. We want to check things like refresh rate and resolution, and make sure that if we’re setting it in Windows for a certain refresh rate and a certain resolution, that it matches the capabilities for the monitor. So you may need both the documentation for your video card and the documentation for your monitor to find some settings that match. For LCD displays, you want to be sure to set things like the native resolution. LCD displays can’t readjust themselves, so if the screen is looking a little blurry, you may want to try different resolutions until you get to the one that is the native resolution for your LCD display.

Some video cards have specialized hardware that allow them to speed up the video by accelerating the video in hardware. Unfortunately, some applications aren’t completely compatible with that. So if you’re watching a movie on your computer, you’re using a media player software, you might want to try disabling the hardware acceleration just to see if it makes a change to that configuration. And of course, there may be newer drivers available that would resolve these conflicts with the hardware acceleration.

If you’re one of the last people still on earth using a Cathode Ray Tube, you may find that magnetic field distortion may cause the tube itself to have discolorations or distortions. One way to resolve this is to use a degaussing tool, either an external one that can be used by professionals, and some displays have the degaussing function built into the display itself. You simply push the Degaussing button and it will degauss that internally to the display. After degaussing, you may find all of these strange colors or distortions are now cleaned up because you’ve now removed that remnant magnetic field.

Our LCD displays contain thousands, in some cases millions, of pixels, so you may find occasionally that certain pixels aren’t working the way they should be. You may run into something like a stuck pixel where one pixel is always bright. It’s always a very white color or red color or green color, and it never changes. You might also find that some pixels never light up. They stay black all the time.

You’ll want to contact the manufacturer of your display to see if there is a warranty replacement available for a certain number of stuck picks or a certain number of dead pixels, or you may be able to use some software to help restart those pixels and get them moving again. But usually after they’re stuck or they’re dead, it’s very, very difficult to get them moving after the fact.

Sometimes, your video display won’t be working exactly the way you might expect. You’ll see artifacts on the screen that should not be there. For instance, you might find unusual graphics. You might want to check the adapter itself. There may be a new driver available, or the operating system may need an update to work properly with that adapter.

You might also run into image persistence where you turn off the display but you’re still seeing images on the screen. That can certainly happen if you have a particular image that’s up there all the time, and when you move to a different screen, the LCDs are so used to being on that image that they aren’t able to change very quickly. Usually, if you power off your LCD display, it will remove any of those persistent images and everything will eventually get back to looking normal.

You might also see things like motion trails. Some of the advanced video features on these cards may not be working exactly the way they should. So you move a mouse across the screen and you’re seeing a very slow trail right after that. So you might want to adjust some of the advanced settings for your adapter card to see if you can improve the performance of the video.

Today’s video cards are very advanced devices, so you want to be sure that you’re keeping updated with the latest drivers. There’s very often bug fixes and the video manufacturers tend to have many releases of video drivers. You might also find that these video cards are getting very hot. There’s a lot of processing that takes place on the video card. They may have multiple fans on the card itself, and you want to be sure that you’re getting very good air flow through your computer so that you can keep it as cool as possible. If you do get a lot of overheating, that might also cause a blue screen of death and a problem associated with the hardware, so you want to be sure to keep your video cards as cool as possible.

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Category: CompTIA A+ 220-802

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