10.6. Troubleshooting Video Adapters Problems If you experience video problems, first check the obvious thingsthat the display has power and is connected properly to the adapter, that no one has changed settings for the adapter or display, and so on. Boot the system in Safe Mode (press F8 during boot to display the Windows boot menu) to load the vanilla Windows display drivers and verify that the adapter and display are functioning properly. If you have another display handy, try connecting it to the problem system to eliminate the display as a possible cause. | Advice from Brian Jepson | You may also want to try the most recent WHQL (Windows Hardware Quality Labs) driverthis may be older than the most current driver. Sometimes, the latest driver posted on the vendor's web site still has some bugs that need to be ironed out while they are working on certification from Microsoft. I think WHQL certification is far from a guarantee of trouble-free operation, though, but it's worth a try if you think you have a buggy driver. |
Once you eliminate those possible causes, the next consideration is whether you've made any recent changes to your video hardware, software, or configuration. If so, that is a likely cause. Sometimes, problems caused by such a change don't manifest immediately. We have, for example, seen an updated Windows video driver function perfectly until one particular program was loaded or another piece of hardware was installed, which caused the system to crash and burn horribly. That means the next step is to change video drivers. If a later driver is available, download and install it. If no later driver is available, try reinstalling the current driver. If problems manifest soon after installing an updated driver, try reinstalling the older driver. Once they are installed and running properly, video adapters seldom fail, short of something like a lightning strike or abusing the adapter by overclocking it. Over 20 years' experience with hundreds of systems, we remember only a few instances when a functioning video adapter just died. Hardware failures are more likely today, not because newer video adapters are inferior to older models, but because they're now pushed harder. High-end video adapters nowadays come with at least a heatsink for the graphics processor, and it's not unusual to see a video adapter on a gamer's system with a fan or even a Peltier cooler installed. If you install a high-performance adapter, make absolutely certain that the fan, if any, has power, and that there is free air flow to the heatsink. Many video problems on systems so equipped are due to simple overheating. Here are some specific problems you may encounter and how to remedy them:
No video or severe video problems occur with a newly installed card. -
The usual cause is that the video card isn't seated properly. Verify that the video card is fully seated and latched. Make sure the display has power and the video cable is connected. Some systems with integrated video automatically disable the integrated video if a standalone video card is detected, but others require you to disable integrated video manually and enable the AGP or PCIe video card in BIOS Setup. Nearly all video adapters that have analog and digital outputs automatically detect the type of connected display and configure themselves properly, but a few require changing a switch or jumper to select the active output port. Similarly, if the video adapter supports dual displays or if you have two video adapters installed, you may have to specify whether your display is connected to the primary or secondary port.
"Out of scan range" or similar message is displayed. -
The display isn't connected to the video adapter or the video adapter is providing a signal at a resolution and/or refresh rate that is not supported by the display. Verify that the display is connected. Restart the system in Safe Mode and select a supported resolution and refresh rate.
Text is too large or too small. -
The video adapter is set for too high or too low a resolution for the monitor size, or Windows is configured to use nonstandard (Large or Very Large) fonts. Right-click on an unused area of the desktop, choose Properties, and modify the settings in the Display Properties dialog and subdialogs to correct the problem. Depending on your preferences and your visual acuity, we recommend running a 17" CRT monitor at 800x600 or 1024x768; a 19" monitor at 1280x1024 or 1600x1200; and a larger monitor at 1600x1200 or higher. | FLAT-PANEL DISPLAYS AND TEXT SIZE | CRT monitors can use any of a range of resolutions while maintaining high video quality. Flat-panel LCD displays are designed to operate at one specific resolution (the native resolution), and provide poor image quality at anything other than native resolution. Rather than change resolution with an FPD, change the font-size options in Windows and/or your applications to display text at optimum size. |
Text is scrambled or appears distorted or in an odd font. -
The probable cause is incorrect video drivers. Download and install the most recent stable drivers for your adapter. If it occurs on a system that had been working correctly, there are several possible causes. If text entered in an application appears in a strange font, but menus and other system fonts are correct, use preferences or options within the application to choose another font. If menus are scrambled only within one application, uninstall and then reinstall that application. If the problem occurs in multiple applications and system applets, system font files may have been corrupted or replaced with older, incompatible versions. The surest cure is to reinstall Windows.
Video problems occur in hot weather or after the system has been running for a while. -
The video card is overheating, for which there are numerous possible causes. If the video card has a fan, make sure that it has power and is spinning freely. If the video card uses a passive heatsink, make sure that the heatsink is not blocked with dust. Verify that the case air vents are not blocked by dust and that the supplemental case fans, if any, are operating properly.
The display shows random black, white, or partial/colored blocks. -
These screen artifacts may appear only when using certain combinations of resolution and color depth, and are not affected by mouse movement or by running a different application. They may be persistent or may appear and disappear seemingly at random. This problem is a result of malfunctioning video memory. Possible causes include an improperly seated video card, overheating, and defective memory on the card. Remove the video card, clean the contacts by polishing them with a new dollar bill, and reinsert the video card. Verify that the heatsink or fan on the card is operating properly and that the interior case temperature is not too high. If none of these actions solve the problem, the video card needs to be replaced.
Video is usually fine but becomes jerky during DVD-Video playback. -
This may result from a slow processor or video adapter, inadequate memory, or by having too many other programs running, but if it occurs on a relatively recent system there are a couple of hardware configuration issues that are more likely causes. First, verify that the DVD drive is operating in DMA mode rather than PIO mode. Second, if you are using a flat-panel display with a digital connector, this problem may be caused by a conflict with USB devices (yes, we know that sounds odd). Disconnect all USB devices, including the keyboard and mouse if you have PS/2 substitutes. Restart the system and check DVD-Video playback. If the problem disappears, try plugging USB devices in separately until you discover which USB device or port is causing the problem. |
