Custom Resolution Utility (CRU)

[digitaltos]

First of all, thank you ToastyX for your hard work. I hate that we still need to rely on the goodwill of random individuals to make our overpriced tech work. Well, it is what it is.

I'm writing about an HDMI audio issue. TLDR: Lenovo T490 laptop -> thunderbolt -> Lenovo 40AY dock -> HDMI -> HDMI switch with audio extractor -> Dell P2419H monitor. Need CRU to force audio through, but this setup with an "audio format extension" block prevents the monitor to connect to the laptop. "No signal" on monitor -> laptop screen turns on -> laptop screen turns off -> monitor display turns black -> "No signal" on monitor -> repeat.

First of all, the Dell P2419H is a mess. The monitor doesn't have speakers or any audio connection, but it shows up as an audio device when you connect it to a computer (all because you can purchase a Dell soundbar to use with it, and apparently that's using audio over HDMI). Now this is true with all laptops I've tried, EXCEPT for my Lenovo T490 (Intel UHD 620 graphics) that doesn't recognize the monitor as an audio output device (maybe if we find out why, that would help me in the long run?). Tried with a clean Win10 and Win11 installs, Lenovo's and Intel's drivers, with or without the HDMI switch, with known good cables, all the usual stuff, but no joy. (We're not dealing with the dock yet.)

After a lot of googling, I've found CRU. Used hdmi-audio.dat, and it worked like a charm. Audio device shows up in Windows, HDMI audio extractor outputs the audio, all good.

Then comes the 40AY dock, a run off the mill Thunderbolt dock. WITHOUT the audio extractor it recognizes the audio device all right (with CRU configured). Of course there's no way to hear any audio this way...

WITH the audio extractor, if I set the usual audio settings in CRU, the monitor is unable to connect, although it tries hard.

The HDMI switch/extractor is a generic chinese model, externally powered, I made sure it gets enough juice. https://ventiontech.com/products/3-in-1-...alloy-type

So, two questions here:

1. How does this monitor communicate that it has audio capabilities? The EDID doesn't seem to reflect it, although I'm not an expert. I'm assuming The T490's graphics driver is what fails to recognize it's capabilities.
2. Any pointers what CRU config settings I could try to make this setup (with the dock) work?