I think it's going to be difficult to get help from the more knowledgeable people here (not me) without having at least a schematic.
That ribbon cable doesn't show any sort of damage other than the missing section of trace. Not really knowing anything about construction of ribbon cables, I can't really say anymore about that, other than it seems odd. If it overheated I would think that the mylar (or whatever the material is) would be damaged. Any way, this video shows a 'creative' repair to a ribbon cable that might be useful:
But if something else is still damaged that caused the ribbon cable to be damaged, it might be a wasted effort or cause further damage, not knowing anything about how the cable might have been damaged in the first place.