My iPhone 14 Pro Max suddenly powered off three days ago even though it had more than 50% battery. It only came back on after I connected it to a charger. Today it shut down again with plenty of charge remaining, but this time it won't start normally, even while plugged in or connected to my Mac. I tried the volume-up, volume-down, and power-button force restart, but the Apple logo only stays on screen slightly longer before disappearing. I also cleaned the charging port, though the phone makes a faint whirring or pressure-release sound while charging. Has anyone dealt with this, and is there anything else I should try before having it repaired?
2 Answers
Since the force restart only briefly shows the Apple logo, keep trying the standard recovery steps, but don’t keep forcing it for hours if the behavior continues. If the Mac detects it, recovery mode may offer an update; avoid restoring it unless you have a backup, because restoring can erase the phone. The unusual charging noise and repeated shutdowns are good reasons to have the device checked professionally.
It may be a hardware or battery problem, especially since it has shut down more than once with plenty of charge remaining. If it manages to boot again, back up everything immediately and arrange an inspection or repair rather than relying on it to stay working.

It eventually started after about two hours of trying. I’m backing it up now, but I’m worried it may shut down again.