● Divergence: An output from one block feeds two or more other blocks. Check each
output in turn, then continue to search for a faulty block in the area that is common to
the incorrect inputs.
● Convergence: Two or more input lines feeding a single functional block. First, check
the inputs at the point of convergence. If all are correct, the fault is beyond the convergence
point. If any input is incorrect, the fault must lie in that input circuit.
● Feedback: The output of a block that is connected to the input of the same block or to
the input of an earlier block.