Quick Answer If your phone does not detect earphones or headphones, first identify whether they use a 3.5 mm plug, USB-C or Lightning connection, or Bluetooth. Test the same headphones with another compatible device and test another known-working headset with your phone. This comparison helps separate a headphone problem from a phone, adapter, port, compatibility, … Read more
Quick Answer When your phone displays No SIM, Invalid SIM, SIM Failure, or cannot connect to the carrier, first restart the phone and confirm that Airplane Mode is off. For a physical SIM, power the phone off and carefully reseat the card. Then test the SIM in another compatible phone or test a known-working SIM … Read more
Quick Answer An “Unknown System Error” message does not identify one confirmed cause. It may come from a specific app, an online service, an account problem, temporary app data, a software conflict, or the phone’s operating system. Take a screenshot of the complete error, note which app was open, and restart the phone. Do not … Read more