Hello, 

My monitor isn't displaying anything on HDMI input. On the DisplayPort I have my 2013 MacPro on it without any issues. I've tried resetting the monitor and resetting the monitor to factory. I've also tried different devices on that port such as: PS4, Samsung DVD/Blu ray player, apple TV. non of them work on the Dell. I've tried them on a TV and I was able to see all of them. Whats strange is that this just started happening. I was able to use my mac on DP and ps4 on HDMI input. I've also tried different HDMI cables. Any advice would be appreciated.  

CN-06X55C-74445-49N-369L

purchased from BH Photo

thank you,