CompTIA A_ Certification All-In-One Exam Guide, Seventh Edition - Michael Meyers [342]
If your LCD makes a distinct hissing noise, an inverter is about to fail. Again, you can replace the inverter if need be.
Figure 19-78 LCD components labeled
Be careful if you open an LCD to work on the inside. The inverter can bite you in several ways. First, it’s powered by a high-voltage electrical circuit that can give you a nasty shock. Worse, the inverter will retain a charge for a few minutes after you unplug it, so unplug and wait for a bit. Second, inverters get very hot and present a very real danger of burning you at a touch. Again, wait for a while after you unplug it to try to replace. Finally, if you shock an inverter, you might irreparably damage it. So use proper ESD-avoidance techniques.
Bottom line on fixing LCD monitors? You can find companies that sell replacement parts for LCDs, but repairing an LCD is difficult, and there are folks who will do it for you faster and cheaper than you can. Search for a specialty LCD repair company. Hundreds of these companies exist all over the world.
Cleaning Monitors
Cleaning monitors is easy. Always use antistatic monitor wipes or at least a general antistatic cloth. Some LCD monitors may require special cleaning equipment. Never use window cleaners that contain ammonia or any liquid because getting liquid into the monitor may create a shocking experience! Many commercial cleaning solutions will also melt older LCD screens, which is never a good thing.
Beyond A+
Video and CMOS
I’m always impressed by the number of video options provided in CMOS, especially in some of the more advanced CMOS options. I’m equally impressed by the amount of disinformation provided on these settings. In this section, I’ll touch on some of the most common CMOS settings that deal with video. You may notice that no power-management video options have been included.
Video
Every standard CMOS setup shows an option for video support. The default setting is invariably EGA/VGA. Many years ago, this setting told the BIOS what type of card was installed on the system, enabling it to know how to talk to that card. Today, this setting has no meaning. No matter what you put there, the system will ignore it and boot normally.
Init Display First
This CMOS setting usually resides in an advanced options or BIOS options screen. In multi-monitor systems, Init Display First enables you to decide between PCIe and PCI as to which monitor initializes at boot. This also determines the initial primary monitor for Windows.
Assign IRQ for VGA
Many video cards do not need an interrupt request (IRQ). This option gives you the ability to choose whether your video card gets an IRQ. In general, lower-end cards that do not provide input to the system do not need an IRQ. Most advanced cards will need one; try it both ways. If you need it, your system will freeze up without an IRQ assigned. If you don’t need it, you get an extra IRQ.
VGA Palette Snoop
True-VGA devices only show 16 out of a possible 262,000 colors at a time. The 16 current colors are called the palette. VGA Palette Snoop opens a video card’s palette to other devices that may need to read or temporarily change the palette. I am unaware of any device made today that still needs this option.
Video Shadowing Enabled
As mentioned in previous chapters, this setting enables you to shadow the Video ROM. In most cases, this option is ignored as today’s video cards perform their own automatic shadowing. A few cards require this setting to be off, so I generally leave it off now, after years of leaving it on.
Other Display Technologies
A few other screen technologies exist, but not so much for computer monitors. Plasma and DLP screens grace many a household’s media room as the primary television display.
Plasma
Plasma display panels (PDP) are a very popular technology for displaying movies. Unfortunately,