Lesson 3: Choosing and Troubleshooting Display Systems

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Matching the components of the display system to the needs of the computer owner is critical to user satisfaction when upgrading or purchasing a system. Knowing the basic steps to troubleshooting a display is key to effecting a quick repair when a component fails to operate properly. This lesson sets out the basic steps to follow in selecting the right class of display hardware for a client, proper care, and troubleshooting common problems.

After this lesson, you will be able to:

• Understand the basic criteria used to advise a customer about display-system options.
• Troubleshoot common display problems.

Estimated lesson time: 10 minutes

Helping a user pick the right display is relatively simple, despite the variety of monitors and adapters on the market.

The display is the part of the system the user interacts with and "sees" the most, and is a major factor in overall performance. Within limits, the buyer needs to get the best display possible.

The CRT size determines the maximum viewable area. For users who will work in only one program at a time, or who don't need high-resolution, a basic monitor should suffice. Graphics intensive applications and multitasking call for larger monitors with faster refresh rates, and display cards to match.

Users who will be using graphics-intensive applications designed for drawing and painting or for CAD and games, will prefer a fast graphics adapter, usually with VRAM or WRAM and high resolution and refresh rates.

Multimedia systems can benefit from cards that offer TV out (usually in the form of an RCA jack that lets the signal be displayed on a regular TV set using the NSTC format), TV tuner, and hardware DVD acceleration.

The usual trade-offs between cost and performance apply, but less than in the days of $3,000 high-end cards. Today, a user can purchase a fast, high-quality adapter for $250 to $300, and can purchase acceptable speed with true-color display for $150 without the extras and expensive memory types.

In recommending a display system, start with your customers' needs, followed by their preferences, and match the two as closely as possible to the available budget. Keep in mind that the display adapter is only part of the equation. Cost can be contained by using a smaller monitor or by accepting slower refresh rates. Cutting the cost excessively can leave clients with a display that does not support the tasks they perform, or that might lead to user eyestrain from the flicker that occurs at slower-than-acceptable refresh rates for the selected resolution.

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.

CAUTION

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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.