[GH-ISSUE #913] Monitor flashes off and on, approx every 2-3 minutes. #567

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opened 2026-05-05 06:15:57 -06:00 by gitea-mirror · 1 comment

gitea-mirror commented

2026-05-05 06:15:57 -06:00

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Originally created by @WalBal on GitHub (Jan 25, 2022).
Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/913

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

Monitor flickers off and on twice, approximately every 3 minutes.

System: Macbook Pro M1 (2021, 14 inch)
Port: Display Port via CalDigit T1+ dock
Monitor: Dell S3221QS

Everything works as expected - volume control (which was my main reason for trying MonitorControl), brightness and contrast - all work as expected. However, the monitor turns off (goes black), back to display, back to black and then stays on again. This happens approximately every 3 minutes.

Expected behavior

Monitor to remain on throughout.

Anything else?

No response

Environment Information (please complete the following information)

- macOS version:
- Mac model:
- MonitorControl version:
- Monitor(s):
- Monitor Cable(s)/Connection(s):
- Apple Silicon/M1 (yes or no):

Originally created by @WalBal on GitHub (Jan 25, 2022). Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/913 ### 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 Monitor flickers off and on twice, approximately every 3 minutes. System: Macbook Pro M1 (2021, 14 inch) Port: Display Port via CalDigit T1+ dock Monitor: Dell S3221QS Everything works as expected - volume control (which was my main reason for trying MonitorControl), brightness and contrast - all work as expected. However, the monitor turns off (goes black), back to display, back to black and then stays on again. This happens approximately every 3 minutes. ### Expected behavior Monitor to remain on throughout. ### Anything else? _No response_ ### Environment Information (please complete the following information) ```markdown - macOS version: - Mac model: - MonitorControl version: - Monitor(s): - Monitor Cable(s)/Connection(s): - Apple Silicon/M1 (yes or no): ```

gitea-mirror

2026-05-05 06:15:57 -06:00

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gitea-mirror commented

2026-05-05 06:16:05 -06:00

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@waydabber commented on GitHub (Jan 25, 2022):

If this happens only after issuing DDC commands via MonitorControl, then it is probably a dock (or maybe a display) firmware issue (or an unlucky combination of both) I am afraid. You can try using a different app like m1ddc or Lunar and see if that causes a similar misbehavior.

I'll convert this issue into a discussion, we can continue it there.

@waydabber commented on GitHub (Jan 25, 2022): If this happens only after issuing DDC commands via MonitorControl, then it is probably a dock (or maybe a display) firmware issue (or an unlucky combination of both) I am afraid. You can try using a different app like m1ddc or Lunar and see if that causes a similar misbehavior. I'll convert this issue into a discussion, we can continue it there.