Place the .bin file in the root directory of the USB (not inside any folders). Clean Installation: Plug the USB into the receiver. Navigate to Menu > Expansion > USB .
This means your current software is too new to be rolled back via USB. You may need to use a RS232 Loader tool and a PC to force the flash. Download Geant 2500 PLUS RETOUR OFFICIEL FBENSAT bin
Ensure you are using the file for the PLUS model and not the older "New" or "Old" versions of the 2500 HD. Place the