MacBook Pro Keyboard Backlight Icona errore?

Sembra che questa icona di avviso indichi che è troppo leggero per accendere la retroilluminazione della tastiera. Un'icona molto fuorviante suggerisce un errore.

Puoi verificarlo tenendo una torcia fino al sensore di luce.

Prova a ripristinare la SMC.

Da qui :

How to reset the System Management Controller (SMC) on your Mac Learn when and how to reset the SMC on an Intel-based Mac.

What the SMC does

The SMC is responsible for these and other low-level functions on Intel-based Mac computers:

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• Keyboard backlighting

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How to know if you need to reset the SMC

These symptoms might mean that an SMC reset is necessary:

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• The keyboard backlight behaves incorrectly.
• The display backlight doesn't respond correctly to ambient light

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How to reset the SMC on Mac notebooks

First, determine whether the battery is removable. Most older Mac notebooks have removable batteries. Mac notebooks that have nonremovable batteries include MacBook Pro (Early 2009 and later), all models of MacBook Air, MacBook (Late 2009), and MacBook (Retina, 12-inch, Early 2015 and later). Learn more about Mac notebook batteries.

If the battery is nonremovable:

1. Choose Apple menu > Shut Down.

2. After your Mac shuts down, press Shift-Control-Option on the left side of the built-in keyboard, then press the power button at the same time. Hold these keys and the power button for 10 seconds.

   If you have a MacBook Pro with Touch ID, the Touch ID button is also the power button.

3. Release all keys.
4. Press the power button again to turn on your Mac.

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If the battery is removable:

1. Shut down your Mac.
2. Remove the battery. If you need help removing the battery, contact an Apple Authorized Service Provider or Apple Retail Store.
3. Press and hold the power button for 5 seconds.
4. Reinstall the battery.
5. Press the power button again to turn on your Mac.

How to reset the SMC on Mac desktop computers

Follow these steps for iMac, Mac mini, Mac Pro, and Xserve. If you have an iMac Pro, skip to the next section.

1. Choose Apple menu > Shut Down.
2. After your Mac shuts down, unplug the power cord.
3. Wait 15 seconds.
4. Plug the power cord back in.
5. Wait 5 seconds, then press the power button again to turn on your Mac.
6. For Intel-based Xserve computers that aren't responding, you can shut down locally or by using remote commands. You can also press and hold the power button for 5 seconds.

How to reset the SMC on iMac Pro

1. Follow these steps for iMac Pro:
2. Choose Apple menu > Shut Down.
3. After your iMac Pro shuts down, press and hold its power button for 8 seconds.
4. Release the power button, then wait a few seconds.
5. Press the power button again to turn on your iMac Pro.