You know what, sometimes you don’t really need to replace with a new one. Sometimes it needs cleaning, troubleshoot, try and error. You may try it yourself before thinking of replacing your whole logic board. There are some useful videos in youtube that helps you to figure out on how to do it. Try checking (Fix Apple Now) & (Louis Rossmann). They are good technicians on how to solve this issue. Hope this helps.
Upgrade MacBook Air A1466 i5 2013 logic board with a newer one 2015