Unresolved Firmware update after E3D print head installation totally failed, blue display on smart display

Hi,

Im Using a Gen 1 Robo 3D printer and tried to update the firmware Marlin 06_10 which already worked as a firmware update a few month ago, so I have used the same code and implemented the changes to the E3D print head (#define temp_sensor 0_5 instead _1 and the max temperatue to 300°C)
Now when I have tried to upload it, the display corrupted and since than the uploads are finished but the display stays blue. If I control the contrast (hardware), it comes to totally white or blue but no information shown on it.
I have tried different programmer with no success.

Does anyone know what the problem could be?

I did it again the same way as in this video.