Some brands provide "Rescue Tools" (like Lenovo/Motorola’s Rescue and Smart Assistant).
Moving to a newer Android version or returning to an older, more stable one. mt6739 firmware
The best place for community-verified ROMs and custom recoveries like TWRP. mt6739 firmware
MT6739 Firmware: The Ultimate Guide to ROMs, Flashing, and Troubleshooting mt6739 firmware