TX2 Custom Carrier Board HDMI Unresponsive

I seem to be having some issues with HDMI on my custom Jetson TX2 carrier board

At first, when plugging in an HDMI monitor to the board (while the computer was live) I had no problem connecting to the monitor. HDMI did not come up upon boot up of the computer, which led me to believe it was a hotplug issue.
However, the next time I plugged the monitor in, I saw only a black screen with the cursor active, but nothing else from the computer.
Now, I cannot get the HDMI to connect at all.

When connecting the TX2 to the development kit, I have no problem seeing HDMI output, so the computer itself has not been damaged at least as far as I can tell.

I’m at a loss to what could have caused this, any tips would be appreciated

I have linked to the relevant schematics below

Unless your carrier is an exact match to the devel carrier I would expect that you need a different device tree between the two. Otherwise you can’t just move the module between carrier boards and expect it to correctly work. Is your carrier board an exact wiring match to the dev carrier?

It is not an exact match to the dev carrier, however like I said initially the HDMI connection was working well. Could there be an issue with the device tree that would “kick in” later?

Please make sure it is following the OEM design guide.

Because HDMI is hot plug it implies that a monitor might work even when it didn’t “really” work (meaning you might have been lucky)…a default setting or a previous monitor may have set something up which happens to work with the monitor. Then when something new is added this might clear out and result in failure.

You might try this, and then plug in the monitor just to see if perhaps the DDC i2c rail wasn’t enabled:

sudo echo 1 > /sys/kernel/debug/tegra_hdmi/ddc_power_toggle