The most comprehensive database for MTK-based "copy" phones. Search for "S21 Ultra" plus your specific MTK model number.
: To be 100% certain, you may need to open the device. The motherboard usually has a laser-etched code (e.g., s21 ultra clone firmware
If the phone boots but has a black screen (backlight but no image), the LCM driver is wrong. You will need to repack the firmware with the correct display driver—a process beyond normal users. The most comprehensive database for MTK-based "copy" phones