BASIC HARDWARE TROUBLESHOOTING TOOLS

1.3.8 BASIC HARDWARE TROUBLESHOOTING TOOLS

There are available several pieces of hardware that can be very helpful in troubleshooting some specific hardware problems.

1. DIAGNOSTIC HARDWARE

If you are a serious home builder or troubleshooter, you may want to consider one or more of the following:

• Loop-Back Plugs: These are small plugs that go onto the serial and parallel ports on your computer and connect the receive to transmit lines to simulate a connection (they connect the port to itself). Using these with a program like Norton Diagnostics allows for full testing of the operation of these ports, whereas without them only the internal portions of the port can be tested.

Note: The type of plugs used by a particular diagnostic utility may be different than the type used by another program made by another company. Check it out before you buy.

• Multimeter/Ohmmeter: An ohmmeter is a device that measures electrical resistance; a multimeter can measure resistance, voltage and current. These devices are used by electricians, electronics designers and repair-people.

A simple ohmmeter is useful primarily for checking for short circuits or open circuits (broken connections, damaged cables, etc.) Multimeters can be used for more extensive electronics testing.

• BIOS POST Cards: It is well-known that the BIOS will, if it finds a problem during its power-on self-test (POST), produce audio "beep codes" and/or video messages that indicate what the trouble is that it found.

What many do not realize is that the BIOS of most PCs is designed to send a stream of test codes to a special memory location as it performs its tests, usually 80h. By using a special card designed to capture and display these codes, you can pinpoint exactly where in the power-on self-test a system is hanging up. This can be extremely helpful in debugging very stubborn systems.

• Test Bed: Some experienced PC repair people keep around an older system that they can use as a test bed for components. It can be very useful to be able to test an unknown device with other components that are known to work, to cut down on the guesswork.

There is also more advanced test hardware available, including devices such as:

9 logic probes,

9 oscilloscopes, and

9 many types of specialized component testers.

These items are generally very expensive and require specific training to be used properly; they are not for the home PC user or even for most hobbyists. Professional test hardware costs thousands of dollars, which is one reason why doing it yourself is often not an option for many kinds of repairs.

2. THE PC TOOL KIT

There are many different types of tool kits available for the computer enthusiast, with tools selected specifically to make the lives of those who work with PCs easier. The right tools can save you a lot of time and help you avoid damage to your equipment (and your hands!)

For the recommended tools and resources, check Lesson 11.1.3. Below are the additional items that the technician’s use on a regular basis:

• Wire Snips: A pair of wire snips for cutting wire and stripping insulation. Some kits include wire strippers for the latter purpose.

• A Large Crowbar: For making adjustments to your hardware.

• A Roll of Black Electrical Tape: They never include this in the kits but they should. Used for wrapping wire ends and insulating components.

• A Soft, Lint-Free Cloth: For cleaning the monitor and other components.

The following items categorize below are "optional, but useful".

They are tools that are used less frequently, or perhaps only in certain circumstances. They are more for someone who does a fair bit of tinkering or who maintains a number of machines:

• Vice Grips: These are incredibly neat tools that have all sorts of uses.

• A Knife: A cutting blade or utility knife of some sort.

The following items are sometimes included in tool kits but rarely to use:

• Soldering Irons: Essential if you are going to try to do repair of circuit boards, but virtually nobody does this (and with good reason). They are also quite dangerous if used improperly.

• Chip Extractors: These are used to remove chips from regular (non-ZIF) sockets, but modern PCs do not generally use thes

Finally, it is a good idea to accumulate a stockpile of spare parts if you are going to be doing work on PCs. It is recommended having the following:

• Screws: Have a "big of bag of screws" of all shapes and sizes that comes in handy when working on various machines.

• Expansion Card Inserts: Save the metal inserts that come out of the back of the case when you put a modem or other card into the PC, as you may need them again later on.

• Drive Faceplates: Similarly, save the plastic faceplates that you remove from the front of cases so you can replace them later if needed.

• Mounting Kits: These sometimes come with retail hard disks and allow you to put a 3.5" drive into a 5.25" bay. Useful when your case has more free 5.25" bays than 3.5" ones.

• Cables: Save any power, IDE, floppy, CD-ROM, or other cables that you accumulate in case you need them later on.

• Keyboard, Mouse, 3.5" Floppy Drive

Keep an extra one of each of these components around to aid in troubleshooting problems by swapping. (Actually, keeping an extra of every major component in the PC is helpful, but the three are mentioned here because they are cheap. Most people can't afford to keep an extra hard disk lying around as a spare.)

3. TROUBLESHOOTING BOOT PROBLEMS

Troubleshooting problems getting the PC to boot up, to the point where the operating system is loaded.

Two ways to diagnose a system that is failing to boot:

1. Follow the full boot process troubleshooting walkthrough.

This is a comprehensive, step-by-step walkthrough of the boot process, and is most useful for diagnosing a boot problem when you are either not that familiar with what happens during booting, or when it is very hard to tell what the problem is.

2. Save time by not walking through the whole boot process, and you know roughly what the problem is, you can jump into the middle of the boot process walkthough using the quick access to boot process troubleshooting.

Before starting troubleshooting the PC boot process, make sure you familiarize yourself with the system BIOS settings. You may want to refer to this procedure, which will help you to set your BIOS settings to safe values to maximize the chances of a successful boot.

You should also make sure there is a clean, viable boot disk in the A: drive before starting the system up if you are planning to boot from the floppy. You may also find it useful to first review

this description of the PC boot process .

Note: All PCs are different, and it is quite possible that your PC may have a somewhat different boot sequence than the "typical" one described here. Just try to follow it as well as you can.