iPhone Call Failed? One Test Separates Line From Phone
One call over Wi-Fi Calling tells you whether the account and the dialler are fine, which moves the whole problem onto the cellular side.
Apple
iPhone Cellular Issue Detected? No Setting Will Fix It
The fix is a reinstall from a computer, started by holding a modifier key while you click Check for Update. It does not erase anything.
iPhone Says No SIM Card? There May Be No Card at All
An iPhone 14 or later bought in the United States has no SIM tray, so the usual reseating advice cannot be followed at all.
iPhone Button Not Working? Volume, Side, or Action
Apple splits a button that is not working into eleven separate symptoms, and how the button feels decides which one you have.
Line on Your iPhone Screen? Wipe It Before You Panic
Debris on the glass and a dead row inside the panel look identical from a foot away. Four free tests tell them apart before you pay anybody.
iPhone Screen Flickering? Unplug It Before Anything Else
Apple puts disconnecting the charger among its first checks, and tells you to try a different outlet. The cause is often the power, not the phone.
iPhone Ghost Touch? Apple Names Six Separate Faults
Apple never says ghost touch. It lists six Multi-Touch faults, and three of them cover a screen acting on its own. Which one you have changes the fix.
iPhone Stuck on Call Ended? Sort It by What You See
Usually the proximity sensor has not released the display. Apple publishes a test you can run yourself, filed under display repair rather than calls.
iPhone Cellular Greyed Out? Start With Screen Time
A dimmed Settings row is a restriction rather than a fault. Apple documents the mechanism on two pages, and neither one is about cellular.
iPhone Showing the Wrong Time? The Switch Has Two Names
The automatic clock is two switches in two menus, and the one that fixes a wrong time zone is filed under Privacy rather than Date and Time.