PC Hardware

Troubleshooting Display Systems

When MDA cards were standard, display systems gave technicians few problems. If the cable was properly attached and the monitor was working, the user got a picture. Today, the wide range of card options and the mix of resolutions, refresh rates, and operating systems lead the user to require help with displays more often.

In spite of the increasing complexity of display systems, most problems can be traced to a few common sources: cables improperly connected or damaged; lack of power; improper monitor adjustment; corrupt or incorrect drivers; and memory conflicts with other components. The following checklist can help you troubleshoot the common display problems you are likely to encounter:

  • Cables: Verify that both the power and monitor-display adapter cables are properly attached. Failure to attach them properly can lead to having no picture at all or to an erratic image with incorrect colors. If the monitor cable has been removed and reseated, bent pins could be the problem. Make sure power is reaching both the PC and the monitor, and that they are turned on.

  • Make sure that the adapter is properly seated in the expansion slot.

  • Boot the system. If you get an image during the POST (power-on self test), but the computer does not load the operating system, suspect memory or driver problems. The same is true if the system repeatedly hangs during Windows operation. Try working in Safe mode. If that succeeds, reinstall the drivers and use Device Manager in the Control Panel System applet to resolve any hardware or memory conflicts.

  • Reset the card to the 640 x 480 in 16-color VGA mode at the 60-Hz refresh rate. If the card works in Normal Mode, in Windows, at these settings, yet fails at higher resolution, color depth, or refresh rates-check the drivers and the capabilities of the display components.

Do not exceed the approved refresh rate for a monitor, even if the adapter can produce a higher scan of the screen. The result will be an unstable or unreadable image, which can damage a monitor very quickly.

If all these enumerated attempts fail, try a different display adapter and/or monitor, or test the hardware set on a different PC to see if one of the components has failed and must be repaired or replaced. In most cases, an out-of-warranty card is not worth repairing; a monitor that has failed should be examined by a specialist.

Lesson Summary

The following points summarize the main elements of this lesson:

  • Choosing a new display system or upgrading components is a matter of matching the user's needs to the available hardware within the budget allowed.

  • Price is not the sole issue when buying a display system. The quality of a display is a major factor in the performance and usability of the computer.

  • PC display problems can cause a variety of symptoms on a system, from screen distortion to failure of the machine to boot.

  • Using a step-by-step approach and walking through possible problem/solution combinations offers a quick way to resolve many display-related difficulties.