Charge the iPhone for an hour, then use the button sequence for its model to force restart it. A black screen that remains after charging and a correct force restart needs Apple service rather than repeated button presses.
A black iPhone screen does not prove that the display has failed. The battery can be deeply discharged, iOS can be frozen, or the phone can be on while the screen is not responding. Start with power and the model-specific force restart before considering a restore.
Charge before diagnosing the screen
Connect a known-good cable and adapter directly to a wall outlet and leave the phone charging for one hour. Inspect the cable and port for damage, debris, liquid alerts, unusual heat, swelling, or odor. Stop if the phone is unsafe to handle; do not keep charging a swollen or smoking battery.
After an hour, look for the low-battery image, vibration, notification sounds, or a computer recognizing the device. Those clues distinguish a display problem from a phone that has no power. Do not use a restore tool merely because the screen is black; a restore can erase data and does not repair damaged hardware.
Use the correct force-restart sequence
For iPhone 8 or later and iPhone SE (2nd generation or later), press and quickly release Volume Up, press and quickly release Volume Down, then hold the Side button until the Apple logo appears. For iPhone 7 models, hold Side and Volume Down. For iPhone 6s or earlier, hold Home and Side or Top. A protective case can obstruct a button, so remove it if safe.
If the Apple logo appears, let startup finish and verify charging, touch, calls, and recent backups. If the phone repeatedly returns to the logo, use Apple’s recovery-mode process instead of force restarting in a loop.
When the phone still stays black
Try one other verified cable, adapter, and outlet. Record whether a computer detects the phone and whether it rings when called. If charging and the correct force restart produce no image, Apple says service may be required. A phone that rings but shows nothing especially points to a display path that needs diagnosis.
Do not disclose your passcode, Apple Account password, or verification code to a repair contact. Activation Lock remains after repair or restore and is not something a third party should bypass.
Primary sources
Interfaces and policies change. We recheck the steps above against these sources and show the verification date at the top of the guide.