Hardware

Take on the blank screen challenge

Users who are staring at a blank screen aren't going to be very productive. Get them working again with these suggestions for troubleshooting vexing monitor problems.


You turn your computer on and instead of it booting up normally and displaying the Windows splash screen, you get nothing. Or perhaps the monitor is working, but the display is beginning to shrink. What do you do? Video display problems can occur on even the most reliable computer systems, and knowing how to troubleshoot them will allow you to quickly get that computer back in the game.

In this article, I will demonstrate how to resolve some basic video display problems. Please realize, however, that it is virtually impossible for me to cover every monitor problem that might occur.

The basics
Your first instinct might be to jump in and start looking for a solution. Sometimes you may have no other choice, but whenever possible, you should take a minute to talk with the user and listen to his or her explanation of the problem.

Then, look at the computer system and the surrounding environment. As simple as this may sound, you should make sure the power lights on the computer, monitor, and any other computer equipment are illuminated.

Take note of things located near the computer system. Occasionally, a simple thing like watering a plant can have an adverse effect on computer equipment. You should also look for signs of a recent soft drink spill.

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Start your troubleshooting with the monitor
After taking in the environment and talking to the user, it’s time to start troubleshooting. If you smell anything out of the ordinary in the area near the monitor and computer (i.e., any smoky or burned odors), replace the device, as well as the power cables and surge suppressor.

When you finally sit down at the computer system, verify that the system is not in Power Save mode. To do this, move the mouse or press a key on the keyboard. The mouse or keyboard action will bring the system out of Power Save mode and back to the previous state.

Check to see if the monitor is turned on. If the power indicator light is not lit, try turning the power on. If this doesn’t solve the problem, reseat the power cable. If the device still doesn’t power on, trace the power cable back to the surge suppressor or power outlet. After making sure that the surge suppressor is turned on, try a different outlet. If you are using a wall outlet, either try a different one or plug something else into the outlet to verify that it is working. You can also use an outlet tester to verify that the outlet has power and is working correctly. These testers can be purchased at most hardware and electronic stores.

If you are still unable to get the monitor to power on, try a different power cable. If this doesn’t resolve the problem, the device may have a faulty power supply, and it should be replaced.

Next, turn your attention to the monitor’s power light. This light not only tells you that the monitor is turned on, but it also tells you if it is receiving a video signal from the computer. If the power light on the monitor is amber, the problem lies with the computer system because the monitor is not receiving a video signal. Verify that the video cable is attached correctly. Some higher-end monitors can accept several types of video adapters and allow you to manually connect the different adapters to the monitor and computer system. Other monitors only provide the familiar 15-pin VGA adapter for the computer. To verify the connection, turn your monitor off and manually reseat the video cable to ensure that the connection is good. If a loose connection was causing the problem, it should be eliminated when you turn the monitor back on. If these steps do not resolve the problem, skip to the next section and begin troubleshooting the computer system.

When the monitor’s power light is green, it is receiving a video signal from the computer. While there still may be a problem with the video settings on the computer, investigate the monitor’s configuration as a source of trouble first.

Most monitors have an onboard menu that allows you to tweak various settings. A common problem you may find is that the brightness and contrast settings are configured too low. A knob that controls these settings can accidentally get turned down. Check these settings. If you find that they have been moved, adjust them until they read properly again.

If the brightness and contrast settings are not the culprit, access the monitor’s Configuration menu and look for other types of problems. Since each brand of monitor has a different configuration menu, you can turn to the manual or visit the manufacturer’s Web site for specific information. However, common things to look for in the Configuration menu are inaccurate power save settings, an incorrectly configured user mode, and resolution settings not supported by the video adapter in the computer system. You might also try setting the monitor back to the factory defaults to erase any incorrect settings.

Finding video problems caused by the computer system
If, after trying all of these suggested techniques, you still find the screen blank, you have virtually eliminated the monitor as the cause of your display issues. So try powering off both the computer and monitor. Turn the monitor back on, and after a few seconds, boot the computer. Under normal circumstances, the computer will run through its boot process by displaying the memory count, system settings, and so forth. Watch for any error messages that are displayed.

If the computer system begins to emit a series of beeps during the boot process, decipher the code by consulting your motherboard manual or the manufacturer’s Web site. Beep codes indicate a hardware problem with the video adapter or motherboard.

Some motherboards have an integrated video display that can be turned off in the BIOS or with a jumper. If your system has one of these, plug the video adapter into it. If a jumper was erroneously removed or knocked loose during a move, your system may be defaulting to the integrated adapter. This adapter setting may also be configured using the BIOS configuration screens. If the onboard video adapter is in use, consult the motherboard manual or manufacturer’s Web site for the correct settings of the expansion slot.

After ensuring that the video cable is attached correctly and the system is using the adapter in the expansion slot, open the computer case and reseat the video card. If this does not resolve the problem, and if the video adapter is a legacy ISA or PCI model, try using a different slot. If this still doesn’t fix the problem, try a video adapter that you know is working that is the same make and model.

If a different video adapter does not resolve the problem, put the questionable adapter in a known good system. If the card in question works in a different system, your problem probably lies with the motherboard.

Miscellaneous hardware-related video problems
Switchboxes, or KVM boxes, allow two or more computers to share a single keyboard, video display, and mouse. If you are troubleshooting a video problem on a system connected to one of these boxes, you must eliminate the switchbox as a possible problem. The easiest way to do this is to connect the monitor’s video cable directly to the video adapter in the computer. If the display problem is resolved, you should ensure that the video cable from the switchbox to the computer is good by reseating the connections or replacing it. If the display problem persists, the switchbox may need to be replaced.

Another possible cause for display problems comes from the motors in devices such as a fan or pencil sharpeners. When placed next to a computer, these devices can cause the display to become distorted and look as though the images are sliding off of the screen. This type of problem is called electromagnetic interference, or EMI, and it is really easy to fix. Simply turn the device off or move it far away from the PC, and the problem should cease. In certain settings, such as a factory or hospital, other equipment near the computer can cause EMI. Since it isn’t always possible to move the computer far enough away to eliminate the interference, such computers are often outfitted with flat-screen LCD monitors because they are not affected by EMI.

When monitors start to go bad, the size of the display will begin to shrink, look like an hourglass, or bow out on the sides. Sometimes you can use the monitor’s configuration menu to temporarily fix the problem, but in the long run, you should replace the monitor.

Today’s monitors have a lot of bells and whistles that are supposed to make your life as a hardware technician much easier. Many of the newer monitors have a feature that will automatically calibrate them to match the settings a computer is configured to use. A malfunction of this feature can cause the display to go black for a moment and then return to normal. This happens whenever the monitor thinks it must recalibrate the settings. Since this is an intermittent problem, it can be frustrating to troubleshoot. If you notice such a problem, you may have to manually configure the device using the monitor’s onboard configuration.

Accessing Windows Safe Mode
Troubleshooting a display problem in an otherwise reliable computer system can be an interesting task. The user may have erroneously made a change and doesn’t know or understand what he or she did. Your best plan of attack is to determine what the user was trying to do and then use Windows Safe Mode to try to track down the actual change that was made. Safe Mode provides basic driver support for things such as the keyboard, mouse, and video display, so you can actually use the system to correct an erroneous setting.

To use Safe Mode with Windows 2000, you will be instructed during startup to press [F8] by the following message: For Troubleshooting And Advanced Startup Options For Windows 2000, Press F8. The Windows 2000 Advanced Options Menu will be displayed, and you will be able to select from the following options:
  • Safe Mode
  • Safe Mode With Networking
  • Safe Mode With Command Prompt
  • Enable Boot Logging
  • Enable VGA Mode
  • Last Known Good Configuration
  • Directory Services Restore Mode (Windows 2000 domain controllers only)
  • Debugging Mode

Select either Safe Mode or Enable VGA Mode, depending on your problem. The difference between the two is that Safe Mode uses the Vga.sys driver, and Enable VGA Mode uses the system’s current video driver, which is set at a resolution of 640 x 480. Safe Mode is probably the better option because the current driver might be causing your display problem.

Common video configuration problems
Once you gain access to the system with Windows Safe Mode, open the display settings by right-clicking the desktop and selecting Properties. Figure A shows the Display Properties dialog box.

Figure A
The possible configurations under the Web and Effects tabs should not cause video problems that would prevent you from using the computer system.


Sometimes, problems can occur when users install new wallpaper, screen savers, and scheme colors. If they have installed software for these features, you should remove it using the Add/Remove Programs icon in Control Panel. Otherwise, check the Background, Screen Saver, and Appearance tabs and elect not to use these features. In the case of a badly configured scheme, you should select the Windows Standard scheme.

The Settings tab (Figure B) is the where a user can inflict the most damage to a system by changing or configuring settings improperly.

Figure B
You should consult the manual or manufacturer's Web site for the appropriate settings for the video adapter and monitor being used with the computer system.


On the Settings tab, the Colors menu shows the current color settings for the monitor. To change these settings, you simply select an option from the drop-down menu. In some instances, choosing an incorrect setting on this menu can cause problems. If you suspect this is so, select the appropriate setting from the menu and then restart the computer.

The Screen Area slider allows you to modify the resolution that the adapter and monitor are using. This also shows the number of pixels in the displayed image. As the numbers get higher, more pixels are used, which increases the amount of information that gets displayed on screen. However, as the setting is increased, the images get smaller. A resolution of 800 x 600 is a good setting for a typical 17-inch monitor. A setting of 1024 x 768 is more appropriate for a 21-inch monitor. Check the monitor size and adjust the slider bar accordingly.

The Advanced button located at the bottom on the Settings tab allows you to configure more complex settings for the video adapter and monitor. When you click on it, you see the screen shown in Figure C.

Figure C
The General tab is relatively mundane, but the Adapter, Monitor, and Troubleshooting tabs provide novice users with many ways to accidentally cause problems with their systems.


The Adapter tab (see Figure D) shows you the current settings for the video adapter.

Figure D


The List All Modes button, as shown in Figure E, allows you to select a valid combination of resolution, color, and refresh rate. If you suspect that the current setting is incorrect, consult the video adapter and monitor documentation for the correct settings.

Figure E


Clicking the Properties button will allow you to view some general information about the video adapter. The Driver tab, shown in Figure F, provides you with the opportunity to view the adapter’s driver settings, as well as uninstall or update the driver. Uninstalling and then updating the drivers is an excellent last resort when you are troubleshooting monitor problems. Before updating the driver, though, visit the manufacturer's Web site to ensure you have the latest version.

Figure F
You can view and modify the resources to which the video adapter is currently assigned by clicking the Driver tab.


The Monitor tab, shown in Figure G, allows you to modify the monitor’s driver by clicking the Properties button, just as you did with the video adapter. You can also change the Refresh Frequency setting that the monitor uses. An incorrect setting will cause the screen to flicker and will cause eye strain when you look at the screen for even a short period of time. This setting is typically configured automatically when you install the video and monitor driver. However, if you need to correct the setting because of screen flicker, reference the monitor’s manual or manufacturer’s Web site to determine the correct Refresh Frequency setting for your monitor.

Figure G
The Refresh Frequency setting reflects the amount of times per second that the screen is redrawn from top to bottom. It is measured in hertz (Hz).


The Troubleshooting tab (Figure H) allows you to control how things appear to move on the screen. As you decrease the hardware acceleration slider bar, your system will correct mouse pointer, drawing, and DirectX accelerated applications problems that may occur.

Figure H
The Full setting is used when the system is working normally.


Conclusion
There are many elements that can cause video display problems. While very simple connection issues cause most of the problems you face, the complicated ones will challenge your abilities. I hope this guide will open your eyes to some simple corrections to perplexing monitor problems.

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