My P50 used to recognize my ASUS dispay. Today, for no known reason, it no longer recognizes that there is an HDMI connection on either port.
P50/P70 Problems Master Thread
Take a look at this. http://support.lenovo.com/us/en/products/Laptops-and-netbooks/ThinkPad-P-Series-laptops/ThinkPad-P50...
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