I have the Thunderbolt 2 Express Dock HD (Model no. F4U085) and I have a question to ask. The dock is attached to a Macbook Pro and everything works fine (audio, ethernet, USB devices etc). However, I cannot connect dual displays to it. My dual monitor setup is as follows: I want to attach one monitor via the HDMI port on the dock and the other via the thunderbolt port on the dock, using a MiniDP to HDMI adapter + HDMI to DVI cable to the external monitor. When I tried the setup, one of the monitors (the one connected to the HDMI port) has no output to it. If i connect it to the HDMI port on the macbook, it shows the output.
According to the official product guide, it says:
Yes. For dual display, at least one (1) display has to be Thunderbolt or Thunderbolt 2 technology. For displays that are not Thunderbolt technology ready, Thunderbolt port is backwards compatible with Mini DisplayPort and dock supports either HDMI or Mini DisplayPort but not both.
How can I connect dual displays to the dock ? I find this somewhat unexplained. Do I need to use an actual thunderbolt cable for one of the monitors , not an adapter? If I buy a thunderbolt cable and a thunderbolt enabled monitor, will I be able to use the HDMI port on the dock for the second monitor ? Or the only possible dual-display scenario is with thunderbolt daisy-chaining? Has anyone had any experience with this issue?
Best Answer
The reason why the dual setup isn't working is that you are using MiniDP & HDMI when dual monitors via MiniDP and HDMI are not supported, as noted in the product guide. You will have to use a Thunderbolt-ready monitor with a Thunderbolt cable to allow both monitors to be driven from the dock.
The reason for this is that your dock is being driven by one Thunderbolt port, which does not allow for daisy-chaining displays (as far as the port on your computer is concerned) unless it is Thunderbolt 2 or the newest revision of DisplayPort. If you were to plug your monitor either into the spare Thunderbolt port on your computer (HDMI on the dock) or use the HDMI port on the computer (MiniDP on the dock) both monitors should work as a workaround.