Oh gosh, that looks like quite piece of work. Could you explain why you replaced the motherboard and the issues that you've had prior to replacing it? It would greatly help everyone so we can assess the situation further. Upon research of this model, this computer is running on integrated (not dedicated graphics).
Would you happen to know if the built in display is directly associated with the display port or is it built in to the motherboard? Did you make sure the connection between your motherboard and the display was securely in? How is the display connected to the motherboard? Have you checked to make sure you have seated the CPU properly?
Does this issue happen to occur during the boot process?
Edited by nkim5252, 30 July 2016 - 01:20 AM.