Doug Smith demonstrates how to use Pulse Injection to find problems with printed circuit boards. He built a small probe that allows him to poke around all areas of the board to see if there is any areas which are sensitive. This method is probably not economical for a hobbyist to use unless you can find the Fisher PG EFT that Doug used in the Apex Electronics bone yard for cheap but I think s simple version of the device could be built in the DIY spirit for $20 or $30. It wouldn’t have all the fancy controls but would get the job done.
If you like the work that Doug is doing have a look at the ESD creating device that you could make for a few dollars. The oscilloscope probe demonstration at the end is quite impressive.