No sound output trough USB 2.0 / DDJ-SX

Hi!

I had manymanymany hours wrestling with this issue and i have no more ideas what to do ?

Controller: DDJ-SX

Soft: Traktor Pro 2 (2.6.6)

OS: Win 8.1 64bit

Laptop: Lenovo Yoga 2 Pro, (i7 (4th gen Intel), 8GB RAM)

Everything else works except no sound output (also master LED's are dead) through USB 2.0 port.

I reinstalled Traktor and all the related drivers (controller, sound devices, chipset and USB). Firmware is up to date, also checked all sound configurations in Traktor and so on ... but still silence. As much i googled this problem, there are several similar cases but no solution. Lucky guess would be that problem hides behind controller's driver and USB-driver mismatch?

Through USB 3.0 port everything works, but I need this fast port for external SSD, so I hope there is some kind of solution for current USB 2.0-port problem? :)

Regards