Raph_395:
I do get the usual blink effect pattern on my Genuino though.I'm pretty sure that my arduino dsoes not have a bootloader;
Those two statements taken together do not seem to be consistent with the advice in Reply #3.
And if you bought a genuine Arduino it would have had the bootloader code when you got it unless it was faulty right from day one.
Have you done anything that might have deleted or corrupted the bootloader code?
...R