LCD or Graphic Chip Failure?

I have here an A1534 1.1 GHz model that has suffered the all to common CPU failure from I guess overheating, which must be common in these fanless Macbooks.... And someone is offering me the same model (But not sure the CPU as 3 versions were made) for next to nothing price, but it comes with this apparent display issue....

I am thinking to just swap over the logic board to make a 'working' unit, but I am concerned that there maybe an irreparable GPU issue other than a faulty display..... to me it looks reminiscent of the scenario when changing the default resolution and then rebooting where these similar lines appear for a split second until the system recognizes the adjusted resolution which to me points to a GPU error as the lines remain as pictured when the system is active. Opinions please?