In a new document posted on its support site, Apple explained why this could happen a temporary drop in brightness of the display of a MacBook Pro with M1 Pro / Max processor or of an Apple Pro Display XDR, the professional monitor that arrived on the market in 2019.
If the ambient temperature of a room is high and if very clear and bright content is playing for an extended period of time, the Liquid Retina XDR Display of a MacBook Pro or Pro Display XDR may temporarily limit the brightness to allow for cooling. .
At the same time, a warning symbol will also be shown in the menu bar or in the Control Center Display menu that signals the activation of a low-power mode that “use limited brightness”.
In case you find yourself in this situation, Apple suggests lowering the room temperature or temporarily turning off the computer to cool it down:
- On MacBook Pro with Liquid Retina XDR display, quit any app that might consume significant system resources.
- Use Apple XDR Display or Pro Display XDR reference mode unless your current workflow requires a specific reference mode.
- Lower the room’s ambient temperature.
- Close or minimize any window with HDR content.
- Choose Apple menu> Sleep to put your Mac to sleep. Let the display cool for 5-10 minutes, then press any key on your keyboard to wake your Mac.
If the problem persists and the ambient room temperature is below 25 °, Apple suggests contacting support.