Now that we have covered the basics of VGA/SVGA, we need to understand although these are the basic standards for all graphics cards today, the industry has moved far beyond with graphics accelerators and 3d rendering. But, before we make the leap into advanced issues, I want to address the basics of troubleshooting video card problems.

The video card does one thing: it sends a signal containing the data from the PC to the monitor. Everything else it does is to improve the quality of the display on the monitor.

No Video Problems
When you turn on a PC, the first thing you expect is to see the monitor blaze to life and display the POST information occurring as the PC reads through the Bios and CMOS settings. When this does not occur, the monitor remains blank, it is almost never a problem with the video card or monitor. You need to start with the basic troubleshooting we discussed in Troubleshooting Basics #01 - #03. 

All video cards send signals to the monitor during the Post phase or start up of a PC based on the Bios video extensions of video card. In other words, a VGA/SVGA video card does not require any software drivers to display data on a monitor beyond the standards implemented in the Bios and the video card. This is important to remember as most problems with video cards is a matter of video card software drivers used by GUI (graphical User Interface) software, such as Windows3.xx or Windows9.xx or WindowsNT. The drivers are implemented to allow color ranges higher than 16 colors to be displayed on a monitor, the resolution used during the POST process. Yes… remember we are talking about basics here. The VGA BIOS (Basic Input/Output System) is the control software residing in the system ROM or BIOS for controlling VGA circuits. With the BIOS, software can initiate commands and functions without having to manipulate the VGA directly. 

If your computer does not generate a display on the monitor during the POST or start up phase, then begin with these troubleshooting tips:

• Is your monitor plugged in and turned on?

• Is the cable connected to the video card?

• If you have removed the video cable, remove it and examine the pins to be sure none of the pins have been bent over or broken off while attaching the cable. Pins bent over can be straightened with a pair of needle-nosed pliers.

• Is the video card pressed completely into the I/O slot (ISA, PCI or AGP)

• You may need to try the monitor and/or video card in anther computer to verify they are working… or try a different video card in the computer to determine if the problem is the video card.

At this point, if the computer is powering up, the fan is running in the power supply and the hard drive/floppy drive are powering up, you need to consider another component may not be properly installed. Remove all cards, (except the video card) and drive connections to the motherboard. Check to see that CPU is installed properly with all the jumpers properly set according to specifications, (overclocking is always a concern here), and remove/reseat the system Ram memory modules. 

Synopsis
If the computer has power, verified by CPU fan, powersupply fan and/or drives running, then it is a matter of the four basic components not functioning properly:

• Motherboard

• CPU

• Ram Memory Modules

• Video card

If you do not have a diagnostic card to insert into the motherboard and most people do not, then the basic trial and error method is the easiest. Remove and replace each with another known working component until you find the faulty part. 

VGA vs. SVGA
What is this? Basically, all video cards use VGA routines to generate basic display to interact with a PCs system BIOS. Then, any advancement on these routines with no universal standard to speak about, to generate display and color above 640x480 with 16 colors is considered SVGA or Enhanced VGA. I believe I can state without exception all video cards sold in nearly a decade would be considered SVGA, capable of displaying a larger realm of color and resolution than basic VGA or 640x480 - 16 colors.

Video Memory vs. Video Speed
One of the most misunderstood components of a video card is the Video Memory. Video memory does not equate to Video speed. Video speed is determined by two major factors: the chipset on the video card and the I/O slot holding the video card, (ISA. PCI, AGP). Video memory only determines the ability to display a certain color depth and resolution, such as 800x600-16million colors. There exists a mathematical formula to determine the required amount of memory on a video card to display varying degrees of color and resolutions, but let us suffice to say that a four (4mg) mg video card can display 1024x768-16million colors, all that is required to work with photographic 2D images. Since it is rare today to find any video cards with less than 4mgs of memory, this is not really much of an issue.

SVGA Problem Solving
One of those sweeping statements that can be made about SVGA video cards today is that the vast majority of problems that arise… and I was say that is 99%, derive from two issues: system resource conflicts or bad video drivers.

Solving issues with video drivers is usually simpler than most people will make it.   If the driver is corrupt, reinstall the driver.  If this does not solve the issue, visit the manufacturer's web site for updated drivers. 

Since the issue of solving system resource conflicts, such as IRQs or memory addresses is more complicated, we will take that issue up in the next Troubleshooting Basics edition. 

Have fun

   Bob