Power off the phone, remove and re-insert the battery, then connect it to the PC while holding the "Boot Key" (usually the center OK button or the Dial button for feature phones).
Extract the downloaded Symphony_B66_HW1_V5_MP_11092019_FSPD.zip package using WinRAR or 7-Zip. Inside, you will find the .pac firmware file, the driver software, and the flashing tool. Step 2: Launch the SPD Upgrade Tool symphony b66 flash file link
Click on the button next to the "Scatter-loading File" field. Power off the phone, remove and re-insert the
Click the folder icon to browse and select the you downloaded. 4. Connect the Phone Turn off your Symphony B66. Remove and re-insert the battery. Click the "Start" button in the flash tool. Power off the phone