Honestly I'm not sure I've ever seen a book book on what your asking. All of my experience/knowledge came from installing alot of hydros and also alot of service calls on them. Sometimes there no answer other than trying things till you figure out the problem of the day
Alot of times isolating/narrowing down the issue area is done by careful consideration of all symptoms and logically ruling things out to methodically narrow down the direction your looking in. Setting up tests or adjusting something to determine if it got worse or better or no affect at all, might tell you your in the ballpark or look at something else entirely
