A friend wants to buy an old iPhone from CL and asked for advice. While I often buy i-devices on CL, I have never actually made a list of things I test. This has inspired to make a list as it will benefit others as well. 0. Look at the cosmetic condition. Look for scratches on screen, back, scuffing on the trim, cracks near earphone jack and charger. Remove any screen protector or case. Here are items to test if it looks fine: 1. Turn silent switch to speaker and then switch it back to vibrate If the phone doesn't vibrate: -either the vibrator is bad or the switch is bad 2. Ask someone to call you: -Test Ringer -Test Speaker phone -Test Earphones 3. Press home button to go to SpringBoard a few times to ensure it isn't stuck 4. Pinch and zoom a few times to test the digitizer 5. Open Safari and Rotate the phone a few times to test accelerometer What else?