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:
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.
