I know these sound obvious, but just have to check if.....
1. Your'e using the cable that came with the device? Not all USB cables work with it or try another cable laying around?
2. Are you actually clicking on the BTC wallet on the device before opening the app?
3. Tried different USB port?
4. Does your OS see the device when plugged in?
That's all I have, good luck! Mine has been working flawless for a long time now.