Hey MPU,
I have had a Dell P2715Q monitor hooked up to my Macbook Pro (retina, 15-inch, mid 2014) I have the DisplayPort of the monitor going into Thunderbolt 2 port on my mac. This worked great for the last 2 years. All of a sudden today it stopped working. I did countless resets, I tried a different macbook pro. No luck.
However, when I used the HDMI to HDMI connection that worked.
I thought about getting a new wire DisplayPort to HDMI (since I can pick that up today from a store locally) and see if the cause is the DisplayPort issue on the monitor.
I thought about getting a new wire DisplayPort to Thunderbolt 2 (will take a day or 2 , not sold locally - Amazon to help)
Thoughts? Best option to retain 4K resolution?