Sony SGP712 Xperia Z4 User's Guide

To perform a factory reset, go to Settings > Backup & reset > Factory data reset. This will erase all data on your device, so ensure that you back up important information before proceeding.
Check the charging cable and adapter for any damage. Try using a different charger to see if the issue persists. Additionally, clean the charging port to remove any dust or debris. If the problem continues, consult a professional technician.
To improve battery life, reduce screen brightness, disable unused apps and services, turn off location services when not needed, and enable battery saving modes available in Settings.
Ensure Wi-Fi is enabled on your device. Restart your phone and router, and forget the Wi-Fi network and reconnect. If the issue persists, update your device's software to the latest version.
Use a USB cable to connect your Xperia Z4 to the computer. Select 'File Transfer' mode on your phone. Your device should appear on your computer, allowing you to drag and drop files between devices.
Perform a soft reset by holding the power and volume up buttons simultaneously until the device vibrates and restarts. If the issue continues, consider a factory reset after backing up your data.
Go to Settings > About phone > Software update. Follow the prompts to check for and install any available updates. Ensure your device is connected to Wi-Fi and has sufficient battery life before updating.
Enable a secure lock screen using a PIN, pattern, or fingerprint. Install updates regularly, download apps only from trusted sources, and use security software to protect against malware.
Go to Settings > Apps. Select the app you want to clear cache or data for, then tap on 'Storage'. From there, you can clear the cache or data for that app.
Restart your device to free up memory. Uninstall unused apps and clear app caches. Consider performing a factory reset if the issue persists, but ensure you back up important data first.