i have a iiyama x2783hsu monitor and i cant change brightnes except this eco button which only dims the brightness a little, i have a windows 10 enterprise computer, also when i go into power options there is no brightness slider bar
Please do try to uninstall/reinstall the graphics card driver that maybe the cause of that issue.
- Go to Device Manager and uninstall the graphics card driver.
- Open Programs and Features and uninstall anything related to your graphics card.
- Download and install the latest driver from the graphics card manufacturer.
- Once installed reboot your laptop then test it again.
- Also do check the manufacturer site of your PC for any updates or hotfixes that may help.