Adapter and Display Troubleshooting


Solving most graphics adapter and monitor problems is fairly simple, although costly, because replacing the adapter or display is the normal procedure. However, before you take this step, be sure you have exhausted all your other options. One embarrassingly obvious fix to monitor display problems that is often overlooked by many users is to adjust the controls on the monitor, such as contrast and brightness. Although most monitors today have a control panel on the front of the unit, other adjustments might be possible as well.

Some NEC monitors, for example, have a focus adjustment screw on the left side of the unit. Because the screw is deep inside the case, the only evidence of its existence is a hole in the plastic grillwork on top of it. To adjust the monitor's focus, you must stick a long-shanked screwdriver about 2" into the hole and feel around for the screw head. This type of adjustment can save you both an expensive repair bill and the humiliation of being ridiculed by the repair technician. Always examine the monitor case, documentation, and manufacturer's website or other online services for the locations of adjustment controls. Most recent CRT and LCD monitors use front-mounted controls with onscreen display (OSD).

A defective or dysfunctional adapter or display usually is replaced as a single unit rather than being repaired. Except for specialized CAD or graphics workstationoriented adapters, virtually all of today's adapters cost more to service than to replace, and the documentation required to service the hardware properly is not always available. You usually can't get schematic diagrams, parts lists, wiring diagrams, and other documents for most adapters or monitors. Also, virtually all adapters now are constructed with surface-mount technology that requires a substantial investment in a rework station before you can remove and replace these components by hand. You can't use a $25 pencil-type soldering iron on these boards!

Servicing monitors is a slightly different proposition. Although a display often is replaced as a whole unit, some displaysparticularly 20" or larger CRTs or most LCD panelsmight be cheaper to repair than to replace. If you decide to repair the monitor, your best bet is to either contact the company from which you purchased the display or contact one of the companies that specializes in monitor depot repair. If your CRT monitor has a 15" diagonal measurement or less, consider replacing it with a unit that is 17" or larger because repair costs on small monitors come close to replacement costs and large monitors aren't much more expensive these days.

Depot repair means you send in your display to repair specialists who either fix your particular unit or return an identical unit they have already repaired. This usually is accomplished for a flat-rate fee; in other words, the price is the same no matter what they have done to repair your actual unit.

Because you usually get a different (but identical) unit in return, they can ship out your repaired display immediately upon receiving the one you sent in, or even in advance in some cases. This way, you have the least amount of downtime and can receive the repaired display as quickly as possible. In some cases, if your particular monitor is unique or one they don't have in stock, you must wait while they repair your specific unit.

Troubleshooting a failed monitor is relatively simple. If your display goes out, for example, a swap with another monitor can confirm that the display is the problem. If the problem disappears when you change the display, the problem is almost certainly in the original display or the cable; if the problem remains, it is likely in the video adapter or PC itself.

Many of the better quality, late-model monitors have built-in self-diagnostic circuitry. Check your monitor's manual for details. Using this feature, if available, can help you determine whether the problem is really in the monitor, in a cable, or somewhere else in the system. If self diagnostics produce an image onscreen, look to other parts of the video subsystem for your problem.

The monitor cable can sometimes be the source of display problems. A bent pin in the connector that plugs in to the video adapter can prevent the monitor from displaying images, or it can cause color shifts. Most of the time, you can repair the connector by carefully straightening the bent pin with sharp-nosed pliers. A loose cable or DVI/VGA adapter can also cause color shifts; tighten the cable and adapter securely.

If the pin breaks off or the connector is otherwise damaged, you can sometimes replace the monitor cable. Some monitor manufacturers use cables that disconnect from the monitor and video adapter, whereas others are permanently connected. Depending on the type of connector the device uses at the monitor end, you might have to contact the manufacturer for a replacement.

If you narrow down the problem to the display, consult the documentation that came with the monitor or call the manufacturer for the location of the nearest factory repair depot. Third-party depot repair service companies are also available that can repair most displays (if they are no longer covered by a warranty); their prices often are much lower than factory service. Check the Vendor List on the disc for several companies that do depot repair of computer monitors and displays.

Caution

You should never attempt to repair a CRT monitor yourself. Touching the wrong component can be fatal. The display circuits can hold extremely high voltages for hours, days, or even weeks after the power is shut off. A qualified service person should discharge the cathode ray tube and power capacitors before proceeding.


For most displays, you are limited to making simple adjustments. For color displays, the adjustments can be quite formidable if you lack experience. Use the OSD controls to adjust color, brightness, picture size, and other settings. To quickly adjust an LCD, try the auto-tune feature available on many models. Even factory service technicians often lack proper documentation and service information for newer models; they usually exchange your unit for another and repair the defective one later. Never buy a display for which no local factory repair depot is available.

If you have a problem with a display or an adapter, it pays to call the manufacturer, who might know about the problem and make repairs available. Sometimes, when manufacturers encounter numerous problems with a product, they might offer free repair, replacements, or another generous offer that you would never know about if you did not call.

Remember, also, that many of the problems you might encounter with modern video adapters and displays are related to the drivers that control these devices rather than to the hardware. Be sure you have the latest and proper drivers before you attempt to have the hardware repaired; a solution might already be available.

Troubleshooting Monitors

Problem

No picture.

Solution

If the LED on the front of the monitor is yellow or flashing green, the monitor is in power-saving mode. Move the mouse or press Alt+Tab on the keyboard and wait up to 1 minute to wake up the system if the system is turned on.

If the LED on the front of the monitor is green, the monitor is in normal mode (receiving a signal), but the brightness and contrast are set incorrectly; adjust them.

If no lights are lit on the monitor, check the power and power switch. Check the surge protector or power director to ensure that power is going to the monitor. Replace the power cord with a known-working spare if necessary. Retest. Replace the monitor with a known-working spare to ensure that the monitor is the problem.

Check data cables at the monitor and video card end.

Problem

Jittery picture quality.

Solution

LCD monitors. Use display-adjustment software or onscreen menus to reduce or eliminate pixel jitter and pixel swim.

All monitors. Check cables for tightness at the video card and the monitor (if removable):

  • Remove the extender cable and retest with the monitor plugged directly into the video card. If the extended cable is bad, replace it.

  • Check the cables for damage; replace as needed.

  • If problems are intermittent, check for interference. (Microwave ovens near monitors can cause severe picture distortion when turned on.)

CRT monitors. Check refresh-rate settings; reduce them until acceptable picture quality is achieved:

  • Use onscreen picture adjustments until an acceptable picture quality is achieved.

  • If problems are intermittent and can be "fixed" by waiting or gently tapping the side of the monitor, the monitor power supply is probably bad or has loose connections internally. Service or replace the monitor.

Troubleshooting Video Cards and Drivers

Problem

Display works in DOS (command-prompt mode) but not in Windows.

Solution

If you have an acceptable picture quality in MS-DOS mode (system boot) but no picture in Windows, most likely you have an incorrect or corrupted video driver installed in Windows. Boot Windows 9x/Me in Safe Mode (which uses a VGA driver), boot Windows 2000/XP in Enable VGA mode, or install the VGA driver and restart Windows. If Safe Mode or VGA Mode works, get the correct driver for the video card and reinstall.

If you have overclocked your card with a manufacturer-supplied or third-party utility, you might have set the speed too high. Restart the system in Safe Mode, and reset the card to run at its default speed. If you have adjusted the speed of AGP/PCI slots in the BIOS setup program, restart the system, start the BIOS setup program, and reset the AGP and PCI slots to run at the normal speed.

Problem

Can't replace built-in video card with add-on PCI, AGP, or PCI Express video card.

Solution

Check with the video card and system vendor for a list of acceptable replacement video cards. Try another video card with a different chipset. Check the BIOS or motherboard for jumper or configuration settings to disable built-in video. Place the add-on card in a different PCI slot. Be sure the card is fully inserted into the slot.

Problem

Can't select desired color depth and resolution combination.

Solution

Verify that the card is properly identified in Windows and that the card's memory is working properly. Use diagnostic software provided by the video card or chipset maker to test the card's memory. If the hardware is working properly, check for new drivers. Use the vendor's drivers rather than the ones provided with Windows.

Problem

Can't select desired refresh rate.

Solution

Verify that the card and monitor are properly identified in Windows. Obtain updated drivers for the card and monitor.

Problem

Can't adjust OpenGL or Direct3D (DirectX) settings.

Solution

Install the graphic card or chipset vendor's latest drivers instead of using the drivers included with Microsoft Windows. Standard Microsoft drivers often don't include 3D or other advanced dialog boxes.

Problem

Can't enable secondary monitor.

Solution

If you are using a dual-head graphics card, make sure the secondary monitor has been enabled in the manufacturer's driver. This can require you to open the Advanced settings for your driver. If you are using two video cards in an SLI (NVIDIA) or CrossFire (ATI) configuration, you must disable SLI or CrossFire before you can enable additional monitors. If you are using an AGP and a PCI video card in separate slots, check the BIOS configuration for primary VGA BIOS. Change the current setting and restart the system. Update video card drivers.

Problem

Can't enable SLI operation.

Solution

Make sure the MIO (SLI bridge) device is properly installed between your video cards (refer to Figure 13.14). If you are not using identical video cards, you must use NVIDIA ForceWare v81.85 or new drivers to enable SLI operation. Make sure both cards use the same GPU family (both must use a 7800-series GPU or a 6800-series GPU, and so on). Make sure SLI operation is enabled in the ForceWare driver.

Problem

Can't enable CrossFire operation.

Solution

If you use the Radeon X800, X850, or X1800 cards, make sure you have paired up a CrossFire Edition and standard Radeon card from the same GPU family. Also, make sure you have properly connected the CrossFire Edition and standard card to each other via the DMS and DVI ports. Update ATI CATALYST display drivers to the latest production version. Be sure you have enabled CrossFire in your display driver.

DisplayMate

DisplayMate is a unique diagnostic and testing program designed to thoroughly test your video adapter and display. It is somewhat unique in that most conventional PC hardware diagnostics programs do not emphasize video testing the way this program does.

I find it useful not only in testing whether a video adapter is functioning properly, but also in examining video displays. You easily can test the image quality of a display, which allows you to make focus, centering, brightness and contrast, color level, and other adjustments much more accurately than before. If you are purchasing a new monitor, you can use the program to evaluate the sharpness and linearity of the display and to provide a consistent way of checking each monitor you are considering. If you use projection systems for presentationsas I do in my PC hardware seminarsyou will find it invaluable for setting up and adjusting the projector.

DisplayMate also can test a video adapter thoroughly. It sets the video circuits into each possible video mode so you can test all its capabilities. It even helps you determine the performance level of your card, both with respect to resolution and colors as well as speed. You can then use the program to benchmark the performance of the display, which enables you to compare one type of video adapter system to another. The Video Edition also supports various types of multimedia projectors and TVs used in home theater and presentation environments.

See the Vendor List on the disc for more information on DisplayMate (formerly Sonera) Technologies, or visit www.displaymate.com.

Some video-card vendors supply a special version of DisplayMate for use in diagnostics testing.





Upgrading and Repairing PCs
Upgrading and Repairing PCs (17th Edition)
ISBN: 0789734044
EAN: 2147483647
Year: 2006
Pages: 283
Authors: Scott Mueller

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