but the strange thing is: when data line 4 (D4 lcd) is connected to the apropiate pin on the arduino (digital 5) -> the lcd is back /online / the circuit somehow is complete agian and i see backlight with collums just like the picture posted before.
This strongly suggests a wiring error. This puts us back almost a week to the post that said: "We need a photograph that allows us to unambiguously follow the six wires that connect between your LCD module and your Arduino."
Don