Symptoms
After you install the April 2016 updates for Surface Pro 3, Surface 4, and Surface Book, or the April 2016 Surface Dock firmware update, your monitors may no longer work. Or, the monitors may not work at the display resolution that you were using before you installed the updates.
Cause
If you have a high-resolution monitor plugged in to the Surface Dock, and the monitor is capable of resolutions of greater than 1920 x 1200 dots per inch (dpi), the issue is probably with the adapter that's connected to it. The first step is to verify the type of connection between the Surface Dock and the monitor.
If the connection runs through a cable or adapter that converts a mini display port to DVI or HDMI, the adapter must be a Passive Type-2 or Active adapter for it to support resolutions above 1920 x 1200 dpi. Passive Type-1 adapters don't support resolutions of 1920 x 1200, and most Passive adapters are not Type-2. Additionally, some Active adapters note in their documentation that they only support 1920 x 1200 resolution, so you must buy a 4K high resolution–compatible one if you want to use a resolution above 1920 x 1200 dpi. Customers must verify the maximum resolution supported by the adapter they are using.Â
Before the Surface Dock April 2016 firmware update, some Passive Type-1 and Active adapters allowed higher resolutions because the Surface Dock displayport firmware was incorrectly allowing it.
Resolution
Use a Passive Type-2 or Active adapter rated for 4K resolution to allow monitor resolutions beyond 1920 x 1200 dpi.
For more information, see Troubleshoot Surface Dock.
