Face ID and screen brightness dimmed! Ambient light sensor replacement

 I can provide you with a general guide on how to replace the ambient light sensor on an iPhone 12 Pro, which might help address issues with Face ID and screen brightness. However, please note that repairing your device yourself might void its warranty, and it can be complex and risky. If your iPhone is still under warranty or AppleCare, it's recommended to contact Apple or an authorized service provider for professional repair.

Tools Needed:

1. Pentalobe screwdriver.
2. Phillips screwdriver.
3. Plastic opening tools.
4. Tweezers.
5. Replacement ambient light sensor.

Note: Before starting, make sure your iPhone is powered off to prevent any accidents.

Steps:

1. Remove the Screws: Use a Pentalobe screwdriver to remove the screws located at the bottom edge of the iPhone near the charging port. Keep these screws safe, as you'll need them later.

2. Opening the iPhone: Carefully insert a plastic opening tool or a thin plastic card between the front and back panels of the iPhone. Gently work your way around the edges to separate the two panels. Be cautious around the edges to avoid damaging any components.

3. Disconnect the Battery: Inside the iPhone, you'll see the battery connector. Use a plastic opening tool to carefully disconnect the battery by prying the connector gently.

4. Remove the Display: There will be several screws securing the display assembly. Use a Phillips screwdriver to remove these screws. Once the screws are removed, gently lift the display assembly, opening the iPhone like a book, and support it at an angle using something like an iSclack tool or an improvised holder.

5. Access the Ambient Light Sensor: The ambient light sensor is typically located near the front-facing camera and earpiece speaker assembly. You might need to remove some screws and gently disconnect any cables that are securing the assembly in place.

6. Replace the Ambient Light Sensor: Carefully remove the faulty ambient light sensor by disconnecting any cables or connectors attached to it. Replace it with the new sensor by connecting the cables properly.

7. Reassemble the iPhone: Follow the steps in reverse to put everything back together. Make sure to reconnect the display cables, secure the display assembly with screws, and reconnect the battery.

8. Test: Power on your iPhone and test the Face ID functionality and screen brightness to ensure that the new ambient light sensor is working correctly.

Remember that repairing modern smartphones, especially ones with Face ID technology, can be quite challenging due to their compact design and intricate components. If you're not comfortable with this level of repair, it's strongly advised to seek professional help from Apple or an authorized service provider.