They would probably tell you what's wrong but no guarantees that is fixed until it drops from the sky, EXPENCIVE.
No one works for free
No one works for free
Quickest/easiest way is to look at the top of the motors.How do I check what motors the drone has? to see prices online for the boards I saw ones for 121$ DJI Phantom 3 Professional Pro Drone - NEW ESC Center Board & MC V2 800kV but I don't know if they are 800kV or 960kV