the only thing I didn't manage to put together was the tiny speaker on my motherboard , It simply doesn't beep at the boot no matter which way I put it
The thing with newer systems and internal speakers is that when they beep, there's something wrong with the system. As long as it's quiet, there's nothing to worry. (At least that applies to MSI MoBos, not so sure about other MoBo manufacturers.)
My Skylake build also has MoBo internal speaker connected and it doesn't beep either when i start my system. Same goes for my Haswell build.
But my old AMD build (from 2011) does beep 3 times at every startup, despite system running just fine. Same goes for my ancient Pentium II (from 1998) that also beeps several times at boot up.
Btw, you should do proper cable management inside your case. The rats nest you currently have is ugly to look at, it's a great dust magnet and also disrupts internal airflow.