MAXX
Years ago i bought a $3300 power book pro 17 inch , top of the range shit, it would not show my audio interface, i bitched to apple and they almost had me convinced it was my audio interfaces fault , so i butchered a usb lead and inserted a current meter to see what exactly what was going on , you are suppose to be able to draw 500 milli amps out of the laptops usb ports this is quite a common thing with all devices, i found out this expensive power book could only deliver 350 milli amps and my device needed 450 milli amps so it could not be found because of lack of power on the very expensive Poerbook Pro , so i bitched again to apple and had to phisically show the shop technicians they were lying with their specs , i eventually got a replacement Laptop as they were aware of this issue but kept it silent from dumb customers , so from there on i dont trust anyone, read the specs and find the actual cause , you might be surprized the outcome.
Good luck