At this time I will share the complete tutorial and how to flash the firmware Symphony H100 Stock Firmware (flash file) from Mediafire. Firmware contains Driver and instructions.
How to Flash Firmware
Step 1: Download and extract the above stock firmware (flash file) on your computer.
Step 2: After extracting you will find the Driver and instruction manual.
Step 3: Install the Usb Manual Driver on your computer and sometimes require a reboot on the computer and then enter recovery mode and disable the signature driver verification. (it will be easier if you connect to internet you will get update download driver at try icon right bottom).
Step 4: Follow the instruction manual to flash the firmware.
[*] Important: Some things might happen like flashing stops when the process runs half or flashing fails before 100% completes, it all happens because some things like your emmc are corrupted, or corrupt firmware files. The solution from me is take it to the service center to avoid further damage. Important warnings you should not ignore before flashing Symphony device, then take a backup of everything as because your personal data will be deleted after flashing the stock firmware.
[*]Note: About stock rom details or Firmware shared on this page is officially launched by a company or official developer that works to help you recover devices such as factory settings. if you ever get a bootloop, software error, update error, hanging and shutdown problems, and other defects related to your device’s operating system will be resolved soon.