Reply to USB connector broken on Kontrol S4

Hey TechTools,
I have a big issue with my S4. I noticed the USB connection was a bit loose while practising last evening so I went and bought a new cable assuming that the cable was the problem. When plugging in the new USB cable today the unit is lifeless. No LED's no computer recognition. I'm running a MacBook pro and I keep getting the error message which I attached to this thread. It basically says that the unit is drawing too much power. The USB connector on the S4 still feels loose when the cable is plugged in. I tried every physical variance possible to fix the issue. Different power sockets in my house, different USB cables and on different computers, installed the newest drivers, cleaned the USB connector with alcohol. Nothing works its still lifeless with the error message popping up. The message also appeared a couple times when the unit was not even on, with just the USB cable plugged in the unit. Would there be current flowing through the unit even when its turned off? I could solder a new USB connector to see if this is the problem but i would assume this would void my warranty, if I still have one (Whats the typical S4 warranty anyway?) Do you believe its worth it to solder a new USB connector to the S4? It could be multiple issues which is my main concern. Help Please. I have a gig tomorrow which is not to mention my girlfriends birthday party so she is just as upset as me.