hello
1. pls check which control board does your printer has , it will be written on the board itself.
2. if it is A20 printer V4.0 board , and you use 3d touch sensor , then you need use firmware A20_G05(CH340 Support 3Dtouch). if you do not use 3d touch , then need use firmware A20_G05(GT2560V4+CH340)
https://www.geeetech.com/download.html?download_id=32