Chosen Solution

I’ve done reflows before with black screens but does this one need a reflow as well?

Hook it up to an external monitor and see if it is showing the same anomaly. Was it doing this before installing Mojave? Try doing from an external drive with a lower system like El Capitan. UPDATE Reseat the display cable and check for any corrosion MacBook Pro 15" Core 2 Duo Models A1226 and A1260 Display Data Cable Replacement