| Problem | Likely Fix | |---------|-------------| | | Close background apps, avoid gaming while charging, remove thick case. | | Slow charging | Use original 18W charger + cable; check for lint in USB port. | | Fingerprint not responding | Re-register fingerprint; ensure no screen protector on sensor (it’s on power button, not under display). | | App crashes | Settings > Apps > [App] > Clear cache / Storage. | | Storage full | Move photos to microSD (Camera settings > Storage location > SD card). | | Can't send SMS | Check Message Center number (Settings > SMS > More > SMSC). | | Auto-rotate not working | Enable from Quick Settings; recalibrate in Settings > Display > Auto-rotate calibration. |