I recently bought a used Elgato Thunderbolt 2 dock off ebay and everything seems to be working fine apart from this display issue.

Here are some details of the issue:

  • The monitor is connected to the dock through the HDMI port of the dock.
  • Upon waking from sleep, the display flashes (the flash that occurs when a display is connected or disconnected) and the monitor no longer works and displays a 'No Signal'.
  • To get the display to work again via the dock, the mac has to be restarted.
  • Ethernet, USB ports and headphone/microphone ports of the dock work when this issue occurs.

Some steps I've taken in an attempt to solve/isolate the issue:

  • Connecting a display directly from the mini display-port/thunderbolt port of the Macbook works.
  • Reconnecting the display and thunderbolt cable does not fix the issue.
  • Power cycling the dock (taking out the power adapter and putting it back in) does not work.
  • Using the second thunderbolt port on the Macbook does not work.
  • Disconnecting the HDMI cable from the dock and using the second thunderbolt port on the dock to connect a display via a mini-displayport adapter does not work.
  • Using another Macbook (a different model, more specifically a Macbook Air) works fine.
  • SMC and PRAM resets have been done already. Does not make a difference.
  • Looking at the console, multiple log entries appear which seem to suggest that the HDMI port is being reconnected multiple times:

Console log

My Macbook Details

  • MacBook Pro (Retina, 15-inch, Mid 2015)
  • List item
  • OSX Mojave 10.14.6
  • Intel Core i7 2.8 Ghz
  • 16 GB DDR3
  • 1TB SSD/Flash Storage
  • Intel Iris Pro/AMD Radeon R9 M370X

I've recently done a clean install, coming from the OSX catalina beta. So suggesting this again is out of the question.

Any help is appreciated.


Turning off "Wake for network access" under energy saver in system preferences seemed to have solved this issue.

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