First of all, back up all the files you wish not to lose (do it using your computer or an SD card). Backing up applications on CITYCALL I8550 is not advisable as they might be the reason your device is malfunctioning. After the hard reset, install them one by one monitoring the reactions of your CITYCALL I8550.
After having saved all personal data, delete them in order to prevent the accidental formatting while performing the hard reset operation.
15 Sep 2023
13 Sep 2023