Hardware Reference
In-Depth Information
Troubleshooting Tips and Techniques
Troubleshooting PC hardware problems can seem daunting to the uninitiated, but in reality it is much
simpler than it seems. Most problems can be diagnosed and corrected using few, if any, special tools
and can be accomplished by anybody who can apply simple deductive reasoning and logical thinking.
PCs have become more complicated and yet simpler all at the same time. More and more complex
internal circuits mean that there are potentially more things that can go wrong—more ways the system
can fail. On the other hand, today's complex circuits are embedded into fewer boards, with fewer
chips on each board and more serial interconnections using fewer pins (fewer wires). The internal
consolidation means that isolating which replaceable component has failed is in many ways simpler
than ever before. An understanding of the basics of how PCs work, combined with some very simple
tools, some basic troubleshooting tips, and logical thinking and common sense, will enable you to
effectively diagnose and repair your own system, saving a tremendous amount of money over taking it
to a shop. In some cases, you can save enough money to practically pay for an entire new system. The
bottom line with troubleshooting PC problems is that a solution exists for every problem, and through
simple practices combined with deductive reasoning, that solution can easily be found.
Repair or Replace?
When dealing with hardware problems, the first simple truth to understand is that you do not usually
repair
anything—you
reinstall
or
replace
it instead. You reinstall because the majority of PC
hardware problems are caused by a particular component being improperly installed or configured. I
remember hearing from IBM many years ago that it had found that 60% or more of the problems
handled by its service technicians were due to improper installation or configuration, meaning the
hardware was not actually defective. This was, in fact, the major impetus behind the plug-and-play
revolution, which has eliminated the need to manually configure jumpers and switches on most
hardware devices. This has thus minimized the expertise necessary to install hardware properly and
has minimized installation, configuration, and resource conflict problems. Still, plug and play has
sometimes been called
plug and pray
because it does not always work perfectly, sometimes
requiring manual intervention to make it work properly.
You replace because of the economics of the situation with computer hardware. The bottom line is
that financially it is much cheaper to replace a failed circuit board with a new one than to repair it.
For example, you can purchase a new, state-of-the-art motherboard for around $100, but repairing an
existing board normally costs much more than that. Modern boards use surface-mounted chips that
have pin spacing measured in hundredths of an inch, requiring sophisticated and expensive equipment
to attach and solder the chip. Even if you could figure out which chip had failed and had the
equipment to replace it, the chips themselves are usually sold in quantities of thousands and obsolete
chips are usually not available. The net effect of all of this is that the replaceable components in your
PC have become disposable technology. Even a component as large and comprehensive as the
motherboard is replaced rather than repaired.
Basic Troubleshooting Steps
According to traditional troubleshooting theory, you can break down almost any troubleshooting
scenario into a set of simple steps modeled after the Scientific Method. These are usually indicated
and explained as follows:
•
Identify the problem (Characterization)
—What are the symptoms? What is the expected
