To resolve the issue of a dim screen while using the Xiaomi 4K Monitor A27Ui, please follow these steps:
First, increase the screen brightness and contrast settings using the monitor’s OSD menu. Sometimes these settings can be set too low, causing the display to appear dim;
Next, verify that the current display mode is appropriate for your content. Using a non-standard or low-brightness mode can affect screen visibility;
If your monitor has HDR enabled, try turning it off temporarily. HDR settings can sometimes cause the screen to appear darker than usual depending on the content being displayed;
Finally, if the above steps do not improve brightness, restore the monitor to its factory settings through the OSD menu.