Geeetech

So i bought the geeetech a10 printer a while ago, this is my second printer.
I was flashing the firmware so i could use the bltouch sensor and now my printer wont work, the lcd is just two rows of black squares in cura it detects the printer but i can only heat up the build plate https://showbox.bio/ https://tutuapp.uno/ https://vidmate.cool/ and nothing else works ive tried to find the default firmware to reflash back to the way it was but arduino keeps giving errors on most files i find.
i followed instruction perfectly i used the right config.h file and set the motherboard in the file but it still will not work please help me.

Sorry not a fix but I am in a similar situation as I have the 2 lines across the display! I did manage to fix it for around a day by re flashing the firmware..but the next day I switched it back on and back to 2 lines across the screen ! Now when I try to re flash nothing changes.now someone on Facebook group suggested it could be the screen thats faulty as it was on there a10m but I don't want to start buying parts with out proper conformation.