Buying a second-hand smartphone is highly economical, but it carries the risk of hidden faults. Follow this checklist during your face-to-face inspection to verify that the device is fully functional:
1. The Screen and Panel Test
Open a completely white image on the display to check for burn-in, dead pixels, or yellow discoloration. Drag an app icon across every corner of the touchscreen panel to ensure the digitizer reads touch inputs perfectly.
2. Camera and Autofocus Verification
Test both the front and rear cameras. Take macro close-ups to verify the autofocus mechanics work correctly, and record a video to check if the optical image stabilization (OIS) runs smoothly without stuttering.
3. Port and Wireless Connectivity Checks
Connect the device to a portable power bank to verify the charging port has a stable connection. Search for nearby Wi-Fi networks and pair with a Bluetooth accessory to confirm wireless antennas are working properly.
4. Audio Quality and Sensors
Make a test call with your SIM card plugged in. Check if the earpiece is loud and clear, test the speakerphone, and verify that the proximity sensor dims the display when you hold the phone to your ear.