When someone says "no trouble found," it means that they didn't find anything wrong or broken. It's like when you check your toybox for missing toys and you don't find any - you can say "no trouble found." Sometimes people have to check things to make sure they are working properly, like when you go to the doctor and they check your ears and throat to make sure you are healthy. If the doctor says "no trouble found," that means everything looks good and you're healthy. So when someone says "no trouble found," it's like saying "everything is okay!"