Hi @Mohd_jun. Sorry to inform you that if you have rooted your phone, it will void the limited warranty as this operation may cause instability issue to the system and hardware damage thus we strongly recommend you don't root your phone. If you already rooted it, you can do factory reset.
Please kindly backup all your data first before doing The Factory Reset. There are 2 way to factory reset your phone.
Warning: this action will erase all your personal information, files and downloaded apps.
In power on state:
Click " Settings" -> " Backup & reset" -> " Factory data reset" -> " reset phone"
In Power off state:
1) Long press Power Key and Volume Up Key
2) Use volume up key to select "Recovery Mode" and use volume down key to confirm.
3) Press Power Key and Volume Up Key together twice to enter recovery mode.
4) Press volume down key to select Wipe data/ factory reset
5) Press volume down key to select " Yes---delete all user data".
If the problem still existed, please contact our service center on http://www.flash3c.com/support/service-center/ to do SW upgrade (need to pay for service), please backup your personal data in advance, thanks!