Navigate to Settings → If the previous owner’s name appears at the top, iCloud is still active.
Important: Ensure the seller fully signs out of iCloud in your presence.

Go to Settings > General > About
Look for “Carrier Lock” – it must read “No SIM restrictions.”
If it states “SIM locked,” the device is tied to a specific carrier.

• Inspect the stainless steel frame (or titanium edges on newer models) for deep dents, bends, or cracks.
• Inspect the bottom screws for any signs of rust.
• Press the Action Button – it should feel crisp and responsive.

• With the screen off, check for scratches, chips, or cracks.
• Test for OLED issues:
• Open a blank page in Notes and zoom in on white. Look for discoloration, yellowing, or image retention (burn-in).
• Display a pure black image in a dim room. Ensure no uneven patches or glowing spots appear.

Check both the rear camera array and front TrueDepth camera for:

• Cracks or scratches on the glass
• Cloudiness or debris inside the lens. Even minor flaws can significantly impact photo quality.

• USB-C Port: Look for lint, debris, or bent pins.
• Buttons: Test Volume, Action, and Side Buttons – each should offer clear tactile feedback.
• Alert Slider (if applicable): Should move crisply between positions without sticking.

Enter Diagnostics Mode or download a Touchscreen Test app from the App Store.
Swirl your finger across the entire screen to check for:

• Dead zones
• Phantom touches
• Unresponsive areas

Go to Settings > Face ID & Passcode and enroll your face.
Verify it works:

• In normal light
• In low light
• At different angles

• Open the Camera app – test every lens (Ultra Wide, Main, Telephoto).
• Record a short video with audio to check the microphone.
• Listen for unusual sounds from Optical Image Stabilization.
• Test the flash and switch between photo/video modes.

• Make a test call. Check earpiece, speakers, and microphone clarity.
• Play a song or video at high volume – ensure no distortion or buzzing.
• Test USB-C audio output with headphones if available.

• Wi-Fi: Connect to a network and load a webpage.
• Bluetooth: Pair with wireless earbuds or seller’s device.
• Cellular: Insert SIM; make a call and use mobile data.
• GPS: Open Maps with Location Services enabled.
• NFC: Check and test NFC.

Go to Settings > Battery > Battery Health & Charging
Check Maximum Capacity:

• Above 90% → Excellent
• 85–90% → Good
• Below 85% → Consider replacement

• Proximity Sensor: Make a call and cover the top front sensor.
• Accelerometer/Gyroscope: Rotate screen; orientation should change smoothly.
• Ambient Light Sensor: Enable Auto-Brightness; screen should dim when covered.

1. Factory Reset: Go to Settings > General > Transfer or Reset iPhone > Erase All Content and Settings.
2. Complete Setup Yourself: Go through setup until reaching the home screen.