Why is one of the displays black when I connect two displays with HDMI pass through?

This is typically caused by exceeding the maximum throughput of the HDMI pass through.  Rally can pass through one 4k display or two 1080p displays. If a 4k signal is sent through HDMI 1, HDMI 2 is then shut off.  To correct this, in computer display settings, change the display resolution on HDMI1 to 1080p60 or lower. If HDMI 1 is set at 1080p60 or lower, HDMI will be repowered and can then pass through a 1080p signal through HDMI 2.

Note: In Windows there are two locations where the display resolution needs to be checked or set. Please make sure the resolution is set to 1080p in both Display settings and Advanced Display Settings as follows:

1. Go to Settings and select System, then Display.

2. Make sure the resolution is set to 1920x1080

3. Click on Advanced Display Settings

4. Make sure the Active signal resolution is also set to 1920x1080.

5. If not, then click on Display adapter properties for Display

6. Click on List All Modes and select an appropriate 1920x1080 mode that has a refresh frequency which is supported by your display

7. The Active signal resolution should now show 1920x1080. If not try a different 1920x1080 mode under List All Modes.