Adapting the circuit in case of problems

In Chapter 7, Building High-Performance Digital Circuits, we discussed various techniques for repairing problems resulting from improper assembly of the circuit board. The base assumption behind those procedures was that the circuit design was correct, and that any issues that arose were related to the assembly process.

You may reach a point where you identify one or more problems with the design of the circuit itself during testing. Once a design problem has been identified, it might be straightforward to revisit the circuit schematic and make the necessary corrections. The immediate problem, though, is that the PCB you are working with cannot be fixed as easily. Ordering a revised board will cost money and take time. It may be helpful to explore the possibility of modifying the PCB in order to implement immediate design changes.

Depending on the specific problem, it may be possible to make some modifications to the circuit board that...