Reply to S2 usb flashing

Hello guys) im a happy owner of this cotroller almost for 6 month andm working in the club till last friday with no issues.
But lastfriday i put my attention on stange behavior of S2 . Im work with Tp 2.1.3 and when one deck is playing and im trying to duplicate it or load new track to another deck, the USB flash light on the controller do short blink. I dont remember this before. Sound its still ok wih no freeze, only the short blink. So im beginning to worry.

Also another new trouble, when i connect S2 to tne mixer p700 in the club - it give a noise from speakers like grounding noise. And nomatter how i connect it RCA or PL. and this noise come only from s2 , i have 2 cdj connected to he same mixer and o noise at all. Also i hear this noise when i do a recording in traktor... So i dont know whatto believe.
If anyone have this issues before?
Thank