I have the same problem. I bought a mouse in America, sent it by mail to Uzbekistan. at the first start both modes worked (2.4 and bt), the next day BT stopped working. I cannot turn on BT mode, the indicator does not blink, the combination of side keys and dpi does not help. in 2.4 mode everything works fine. if hold down the left, right and wheel, the indicator blinks quickly and dfubasilisk appears in the search. under warranty I can not return, since there is no way to return back to America. the mouse broke on the second day of use. Great !