Power Led is flickering but not working

I bought brand-new UD-3900.
The Power Led is flickering (Blue led) and it’s not working with my laptop.
I also Put UD-3900 USB cable to another PC, but it also not working.
It seems PCs cannot sense UD-3900 because there’re no beeps and no detection when I put the USB cable into my PCs.

I used UG39DH1 before, I sure I followed your instruction well.


Thanks for posting here! I’m sorry to know about the issue you are having with our dock. Just shoot us an email at support@plugable.com with your amazon order ID along with a link to this thread and we will take care of the issue.