In the Navy we used to call this "DIVE BOMBING". Boucing around changing parts that do not need changing. Big difference between a parts changer and a trouble shooter.
The Navy taught a "Logical Trouble shooting procedure" step by Step. Do not change two things only one at a time or you will never know what fixed the problem!
"Fly Navy" This advice works for everything in life........well almost everything,
Ken
Lots of good advice from all these guys!