Why closing your MacBook lid does not turn off the mini-LED screen (and how to fix it)

说明与用途

在 Apple Silicon MacBook 关闭盖子时，mini‑LED 显示屏仍保持开启，导致发热和电池快速耗尽。Swift 工具 Dopamine 在盖子关闭时将背光降至 0.0 nit，同时保持 CPU 活动，从而降低热量并节省电量。

问题

When running long tasks on Apple Silicon MacBooks with the lid closed, the mini‑LED display backlight remains on, causing excessive heat and battery drain.

结果

Dopamine effectively turns off the mini‑LED backlight when the lid is closed, reducing heat and battery drain while keeping the system awake.

工作流

• Detect lid close via IOKit event listener on IOPMrootDomain service.
• When lid closes, set hardware backlight to 0.0 nits (DPMS sleep) while maintaining keep‑awake assertion.
• When lid opens, restore previous brightness smoothly.
• Provide a lightweight Swift menu‑bar app with no Electron bloat.
• Ensure code signing and notarization for security.
• Install via Homebrew cask or download DMG from website or GitHub.

证据

On Apple Silicon MacBooks, when you close the lid with a keep‑awake assertion active (without an external monitor connected), macOS does NOT turn off the Liquid Retina / mini‑LED display backlight.

来源

The moment the lid closes, Dopamine drops the hardware backlight to absolute 0.0 nits (complete blackout / DPMS sleep) while maintaining the CPU/GPU keep‑awake assertion.

来源