I purchased a DragonBoard last month and just powered it up for the first time today, using the given instructions here 'Starting the board for the first time' with a 7" HDMI display and a 9V PSU. I first tried the stock image, Android and it didn't put out any HDMI. As such I then reached out to try Debian Linux too. It did not display HDMI either to my display.
I validated the cable, input port and display using a different HDMI device. With that cable & port driving the display, worked just fine so the display and connection is ok. How to debug further? Thoughts?
sooooooo strange. And a huge bummer!