[GH-ISSUE #1179] BenQ BL2420PT weird problems #687

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opened 2026-05-05 06:30:14 -06:00 by gitea-mirror · 1 comment

gitea-mirror commented

2026-05-05 06:30:14 -06:00

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Originally created by @GroovyDrifter on GitHub (Sep 16, 2022).
Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/1179

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

BenQ BL2420PT volume control not working using HDMI, Brightnes works but 60% bar is 100% brightness.
Same monitor, same computer, using a Thunderbolt 3 to Displayport cable all works perfect, volume works and the full scale of brightness is used.
Same monitor, other computer, using HDMI port, volume works perfect and brightness gets to 100% at 60% bar in app.

Expected behavior

The expected behaviour is that this monitor with this software worked the same no matter the computer or port in that computer/monitor used.

Anything else?

Previously I used this BenQ BL2420PT monitor with different computers but always via HDMI and Monitor Control never failed, even when used throug a KVM, until I adquired a M1 Mac Mini.

I suspect the problem is in the HDMI output of the Mac Mini M1 (2020) that may be limited by design in some way. I can do further tests by request.

Environment Information (please complete the following information)

- macOS version: 12.6 Monterey
- Mac model: Mac Mini (2020) M1
- MonitorControl version: v4.1.0
- Monitor(s): BenQ BL2420PT (two of them same behaviour)
- Monitor Cable(s)/Connection(s):HDMI & Thunderbolt-Displayport
- Apple Silicon/M1 (yes or no): yes

Originally created by @GroovyDrifter on GitHub (Sep 16, 2022). Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/1179 ### 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 BenQ BL2420PT volume control not working using HDMI, Brightnes works but 60% bar is 100% brightness. Same monitor, same computer, using a Thunderbolt 3 to Displayport cable all works perfect, volume works and the full scale of brightness is used. Same monitor, other computer, using HDMI port, volume works perfect and brightness gets to 100% at 60% bar in app. ### Expected behavior The expected behaviour is that this monitor with this software worked the same no matter the computer or port in that computer/monitor used. ### Anything else? Previously I used this BenQ BL2420PT monitor with different computers but always via HDMI and Monitor Control never failed, even when used throug a KVM, until I adquired a M1 Mac Mini. I suspect the problem is in the HDMI output of the Mac Mini M1 (2020) that may be limited by design in some way. I can do further tests by request. ### Environment Information (please complete the following information) ```markdown - macOS version: 12.6 Monterey - Mac model: Mac Mini (2020) M1 - MonitorControl version: v4.1.0 - Monitor(s): BenQ BL2420PT (two of them same behaviour) - Monitor Cable(s)/Connection(s):HDMI & Thunderbolt-Displayport - Apple Silicon/M1 (yes or no): yes ```

gitea-mirror closed this issue

2026-05-05 06:30:16 -06:00

gitea-mirror commented

2026-05-05 06:30:19 -06:00

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@the0neyouseek commented on GitHub (Sep 16, 2022):

Hi @GroovyDrifter

I suspect the problem is in the HDMI output of the Mac Mini M1 (2020) that may be limited by design in some way

This exactly that. Unfortunately, on apple silicon macs, the HDMI port does not allow for DDC (hardware) control, you can disable hardware control by unchecking "Use Hardware control" in MonitorControl Preference or use a usb-c cable.

Have a nice day !

@the0neyouseek commented on GitHub (Sep 16, 2022): Hi @GroovyDrifter > I suspect the problem is in the HDMI output of the Mac Mini M1 (2020) that may be limited by design in some way This exactly that. Unfortunately, on apple silicon macs, the HDMI port does not allow for DDC (hardware) control, you can disable hardware control by unchecking "Use Hardware control" in MonitorControl Preference or use a usb-c cable. Have a nice day !

gitea-mirror referenced this issue

2026-05-05 07:06:44 -06:00

[PR #687] [MERGED] German translation – added missing string and standardised translation #1174