Dell U2718Q + MacBook Pro 2015 Displayport Problems

I upgraded to a 2019 16” MBP + a CalDigit TS3 dock, and haven’t experienced this issue…yet.

I have a 2015 15” MacBook Pro, which I use with a Dell U2718Q monitor.

For some reason every 3-6 months the monitor will stubbornly refuse to connect over the Thunderbolt 2/Mini DisplayPort, and will only function over the laptop’s built-in HDMI port.

To resolve this issue, you can reset the Dell monitor.

Steps to reset Dell Monitor

  • Shut down your MBP completely
  • Disconnect all cables from the monitor and the MBP
  • Turn on the MBP and log in normally.
  • Press and hold the monitor power button for 10 seconds
  • Reconnect power to monitor
  • Reconnect DisplayPort to mini DisplayPort cable to the monitor first, and then the MacBook Pro.
  • Turn monitor on, and switch source to DisplayPort if needed.

Sidenote: the U2718Q has otherwise been fantastic. I picked up a second one a year later. Dell has an updated model U2720Q that now features USB-C (that puts out enough power to charge a 16” 2019 MBP).