Solution:

What is Troubleshooting?

• Troubleshooting is the process of recognizing, isolating, and correcting a fault or failure in a system. To be an effective troubleshooter, you must understand how the system works and be able to recognize incorrect performance.

• Troubleshooting can be at the system level, the circuit board level, or the component level. Today, troubleshooting down to the board level is usually sufficient.

• Once a board is determined to be defective, it is usually replaced with a new one. However, if the circuit board is to be saved, component-level troubleshooting may be necessary.

Half-Splitting Method:

• In this procedure, you check for the presence or absence of a signal at a point halfway between input and output.

• If the signal is present, you know the fault is in the second half. If the signal is absent, you know the fault is in the first half. Then you split the defective half in half and check for a signal.

• The process is continued until a certain area of the system has been isolated. This may be a single circuit board in a system with many circuit boards or a component on a given circuit board.

• In a large system, this procedure can save a lot of time over moving down the line checking each block or stage as you go.

• This method is usually best applied in large complex systems. Figure is a simple illustration of this method.

• The system is represented with the four green blocks. Additional steps are added to left or right for additional blocks.

Signal-Tracing Method:

• Signal tracing is the procedure of tracking signals as they progress through a system from input to output.

• Signal tracing can be used with half-splitting, where you check for a signal at each point from where the absence of a signal was detected.

• Signal tracing can also begin at the output where there is an incorrect or absent signal and go back toward the input from point to point until a correct signal is found.

• Also, you can begin at the input and check the signal and move toward the output from point to point until the correct signal is lost.

• In both cases, the fault would be between the point and the output. Of course, you must know what the signal is supposed to look like in order to know if anything is wrong.

• Figure illustrates the concept of signal tracing.