The most inexpensive way to solve an issue is of course to use known troubleshooting steps . The repair shop uses that method, thing is, they have bins of known good parts and they will swap out til the issue is solved, for the home user, our resources are , for the most part , limited . So, with that in mind, do what you can , before you have no choice but to take it to a Repair Shop. Good luck with this issue .