Chromecast Ultra is not working with 4K HDR monitor with HDMI 2.1, only outputting 720p

[jasonycw]

I have a Chromecast Ultra connected to a 4K monitor with HDMI 2.1 ports, but the monitor reports that Chromecast Ultra only outputing a 720p signal.

I tried plugging in the same Chromecast into other 1080p monitor with HDMI 2.0 and 4K TV with HDMI 2.1, both seems working as expected, outputting 1080p and 4K signal.

Is there something wrong with 4K monitors' HDMI 2.1 ports with Chromecast Ultra's HDMI 2.0a integration?

[Jeran]

Hey there jasonycw,

Since the Chromecast was designed for use with TVs, sometimes it can be a bit finicky when using it with a monitor. The first thing I would check is if your monitor meets the Chromecast requirements. I would also check the settings on the monitor itself to see if there is a setting that could affect either the quality or the HDMI port, such as a power saving mode.

Best regards,

Jeran

[jasonycw]

Yes, the monitor is 27M2V, with the same HDMI2.1 port connected to a PC, it does support HDCP and can stream Netflix and Youtube 4K HDR content properly.

But with Chromecast Ultra connected, only 720p is output towards the monitor. I also make sure to turn off all power saving feature on the monitor's OSD.

One weird quirk is, if I switch the whole monitor from HDMI2.1 mode to HDMI2.0 through it's OSD, Chromecast can then output 4K HDR. But this changes limit the monitor to be HDMI2.0 only which is not suitable to PC usage. This is why I want to know I want Chromecast to work with HDMI2.1 on monitor

[Jeran]

Hey jasonycw,

I apologize for the late response on this thread, and thank you for your patience! There are a few possible explanations for why your Chromecast Ultra is not working with your 4K monitor. 

First, it's possible that the HDMI 2.1 ports on your monitor are not compatible with the Chromecast Ultra's HDMI 2.0a integration. This is unlikely, as most 4K monitors with HDMI 2.1 ports are compatible with the Chromecast Ultra.

Second, it's possible that there is a problem with the Chromecast Ultra itself. Try restarting the Chromecast Ultra and your monitor, and make sure that both devices are plugged into a power source.

Third, it's possible that there is a problem with your HDMI cable. Try using a different HDMI cable and see if that fixes the problem.

Let me know if the problem persists, and we can have you speak with Chromecast Support to dig a little deeper.

Best regards,
Jeran

[jasonycw]

The monitor's HDMI 2.1 is definitely working as I can connect a PC with 4K 120Hz HDR running.

I have already restarted Chromecast Ultra multiple times with no improvement and of course both are connected to the bundled power source.

The HDMI cable is non removable from the Chromecase Ultra, there is no extra HDMI cable between that and the monitor.