Troubleshooting the Video System
The PC’s video system consists of the monitor and the video card. Most video system
problems are easily detected because they are visual and show up on the monitor. While
the monitor can have problems, the video card is the cause of most video problems on a
PC. One thing to remember when troubleshooting the video system is that no matter how
high-end the video card may be, it is limited by the abilities of the monitor. If the screen is blank or dark, check to see if the monitor is plugged into a
power source, the power cord is connected to the monitor, and the monitor
cable is connected to the PC. Many newer monitors use a double-ended
VGA cable that has a HD-15 connector at the monitor end as well as the video
card end. If the cables are okay, reseat the video card.
The most common video problems are refresh rates, resolution, and color
depth settings. These problems are easily solved through the Display
Properties applet on the Windows system. See Chapter 21 for information
on setting these properties.
If the monitor’s display is blank, scrambled, distorted, or has multiple layers
of the same images, the monitor is unable to handle the video card’s output.
Another very irritating symptom of a mismatch between the monitor and
video card is a high-pitched tone coming from the monitor. Use the Windows
Display Properties applet to change the color depth and the resolution levels
to a more compatible setting. Your monitor and video card documentation
should have a recommended refresh rate for the monitor. The tools you need
to change the refresh rate are accessed through the Advanced button on the
Windows Display Properties window.
If after changing the refresh rate the monitor image is unreadable, reboot the
PC into Windows Safe Mode and change the refresh rate to a lower setting and
reboot the PC into normal mode. To boot a Windows system into Safe Mode,
choose Shutdown from the Start button’s menu and select Restart from the option
list. When the Windows screen appears during the boot (the LOGO.SYS screen),
press theF8key.
It is very common that the device driver included with Windows or shipped
with a video card is obsolete. Visit the manufacturer’s Web site for a current
device driver for the video card.Troubleshooting the Power Supply
A weak or faulty power supply can create a number of problems for the peripheral de-
vices installed inside the system unit, especially the motherboard and disk drives. Unex-
plained or intermittent memory or hard disk errors are commonly caused by a faulty or
failing power supply. Extended periods of low voltage can damage the hard disk drive as
much as over-voltages can burn out the motherboard and memory.(^636) PC Hardware: A Beginner’s Guide