This troubleshooting page needs some serious overhaul. If your laptop won't turn on, then there are MANY issues which could cause this issue. Only replace the logic board if you are 100% sure that the logic board is the cause of the issue. If you are having trouble with your macbook pro, try researching the issue on google or take it to a professional. That being said, the iFixit replacement guides for the macbook are excellent, so use those if you do determine the cause of a problem.