Hi, I'm new to 3D printing and I bought a Geeetech i3 pro b and I've been using it for a while and I saw on youtube that I can update the software. I watched the videos and I flashed the firmware through the prusa app on win 10 and that completely ruined my printer because now when I turn it on the LCD display shows nothing and only lights up green. I tried to use arduino uno as bootloader but to be honest i don't know anything. If someone can help me, I would be very grateful. the printer is powered by an atmega2560 board.

Thanks!!