Finding a firmware file is critical, as using the wrong version can brick the device or result in a "sound only" black screen. Why Use a Firmware Repack?
Select the .img or firmware file from your verified repack folder.
Connect your X7 to a PC, select "Power and Data," and copy your existing game folders to your computer. Step-by-Step Installation Guide
If you use a Miyoo repack and lose sound, you may need to edit options.cfg MODULES_CUSTOM=1 or use the image instead of Unrecognized Device: