Watch serial console: The backlight should illuminate during SPL phase if GPIO config is correct.
The firmware is usually distributed as a single image file containing the bootloader, kernel, recovery partition, and system data. allwinner+a133+firmware+work
If you are swapping from LPDDR3 to DDR4 chips, you must recompile boot0 with new dram_para . Failure leads to "dead bus"—no serial output. Watch serial console: The backlight should illuminate during