[GH-ISSUE #658] Dell U2720Q does not allow brightness control when DCI-PC color space setting is enabled #454

New issue

Closed

opened 2026-05-05 06:02:04 -06:00 by gitea-mirror · 1 comment

gitea-mirror commented

2026-05-05 06:02:04 -06:00

Owner

Originally created by @Marcopohlo on GitHub (Oct 2, 2021).
Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/658

Before opening the issue, have you...?

Searched for existing issues
Read through the Monitor-Troubleshooting Wiki
Updated MonitorControl to the latest version (if applicable)

Describe the issue

Brightness doesn't work at all on my U2720Q.

I've experimented with betas and also once tried to build it directly from Xcode, could this be related? I mean could some setting be altered by this experimenting?

Expected behavior

I should be able to adjust monitor brightness through MonitorControl

Anything else?

No response

Environment Information (please complete the following information)

- macOS version: 11.6 Big Sur
- Mac model: M1 Mini
- MonitorControl version: v3.1.1 (build 3096)
- Monitor(s): Dell U2720Q
- Monitor Cable(s)/Connection(s): USB-C
- Apple Silicon/M1 (yes or no): yes

Edit: So I tried to meddle with the settings a bit and discovered that contrast was working correctly. Then I tried to reset the monitor to factory settings and suddenly everything was working until... I changes color preset to DCI-P3.

When it's in DCI-PC, brightness doesn't work but as soon as I switch it to any other settings, everything works just fine. So sticking with sRGB for now.

Don't know how to proceed with this issue? Is this a monitor specific issue that DDC does not work when DCI-P3 is set? Or MonitorControl issue?

Thank you for the good work guys!

Originally created by @Marcopohlo on GitHub (Oct 2, 2021). Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/658 <img width="803" alt="Screenshot 2021-10-02 at 13 27 34" src="https://user-images.githubusercontent.com/6273948/135714135-0b642af4-bfc6-43b9-93d4-da71c844dfa6.png"> ### Before opening the issue, have you...? - [X] Searched for existing issues - [X] Read through [the Monitor-Troubleshooting Wiki](https://github.com/MonitorControl/MonitorControl/wiki/Monitor-Troubleshooting) - [X] Updated MonitorControl to the latest version (if applicable) ### Describe the issue Brightness doesn't work at all on my U2720Q. I've experimented with betas and also once tried to build it directly from Xcode, could this be related? I mean could some setting be altered by this experimenting? ### Expected behavior I should be able to adjust monitor brightness through MonitorControl ### Anything else? _No response_ ### Environment Information (please complete the following information) ```markdown - macOS version: 11.6 Big Sur - Mac model: M1 Mini - MonitorControl version: v3.1.1 (build 3096) - Monitor(s): Dell U2720Q - Monitor Cable(s)/Connection(s): USB-C - Apple Silicon/M1 (yes or no): yes ``` **Edit:** So I tried to meddle with the settings a bit and discovered that contrast was working correctly. Then I tried to reset the monitor to factory settings and suddenly everything was working until... I changes color preset to DCI-P3. When it's in DCI-PC, brightness doesn't work but as soon as I switch it to any other settings, everything works just fine. So sticking with sRGB for now. Don't know how to proceed with this issue? Is this a monitor specific issue that DDC does not work when DCI-P3 is set? Or MonitorControl issue? Thank you for the good work guys!

gitea-mirror closed this issue

2026-05-05 06:02:07 -06:00

gitea-mirror commented

2026-05-05 06:02:10 -06:00

Author

Owner

@waydabber commented on GitHub (Oct 2, 2021):

Hi, this is definitely a monitor specific issue. DDC control seems to work but the display does not allow the setting to take place in specific color space settings.

I'll convert this to a discussion as owners of this display model might find the info important - thanks for sharing the solution!

@waydabber commented on GitHub (Oct 2, 2021): Hi, this is definitely a monitor specific issue. DDC control seems to work but the display does not allow the setting to take place in specific color space settings. I'll convert this to a discussion as owners of this display model might find the info important - thanks for sharing the solution!