**Hi, I'm an experienced iPhone expert. I'd be delighted to guide you with the steps to restart your iPhone when the screen is black.**

Method 1: Force Restart

1. **Press and quickly release the volume up button.**
2. **Promptly press and quickly release the volume down button.**
3. **Immediately press and hold the side button (power button).**
4. **Keep holding the side button until the Apple logo appears.**

Method 2: Recovery Mode

1. **Connect your iPhone to a computer using a USB cable.**

2. Put your iPhone into recovery mode:
- For iPhone 8 and later: Press and quickly release the volume up button, then press and quickly release the volume down button, then press and hold the side button until you see the recovery mode screen.
- For iPhone 7 and iPhone 7 Plus: Press and hold both the volume down button and the side button until you see the recovery mode screen.
- For iPhone 6s and earlier: Press and hold both the home button and the side button until you see the recovery mode screen.
3. **On your computer, open iTunes (or Finder on macOS Catalina or later).**
4. **When prompted, click "Restore".**
5. **Follow the onscreen instructions to complete the recovery process.**

Note: Recovery mode will erase all data from your iPhone, so make sure you have a backup before proceeding.

Method 3: DFU Mode

Warning: DFU mode is a low-level recovery mode and should only be used as a last resort. It can cause data loss, so make sure you have a backup before proceeding.

1. **Connect your iPhone to a computer using a USB cable.**

2. Put your iPhone into DFU mode:
- For iPhone 8 and later: Press and quickly release the volume up button, then press and quickly release the volume down button, then press and hold the side button. Continue holding the side button until the screen turns black. Then, press and hold both the volume down button and the side button for 5 seconds. Release the side button but keep holding the volume down button for another 10 seconds.
- For iPhone 7 and iPhone 7 Plus: Press and hold both the volume down button and the side button until the screen turns black. Then, release the side button but keep holding the volume down button for another 10 seconds.
- For iPhone 6s and earlier: Press and hold both the home button and the side button until the screen turns black. Then, release the side button but keep holding the home button for another 10 seconds.
3. **On your computer, open iTunes (or Finder on macOS Catalina or later).**
4. **You should see a message in iTunes (or Finder) saying that your iPhone is in recovery mode.**

5. Click "Restore".
6. **Follow the onscreen instructions to complete the recovery process.**

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Reset. If restarting your iPhone doesn't solve the dark-screen problem, reset the device. Do this by holding down the "Sleep/Wake" button and the "Home" button at the same time for at least 10 seconds. Hopefully, you will see the Apple logo appear before you release the buttons.read more >>