I have wd 4tb harddrive and i have connected it to the C7 ac1750 on the usb port to access it via ftp network. It works well but i have noticed that the harddrive never goes into sleep more as the led light always keep blinking. I'm afraid that that this might spoil my drive. I have tried formatting the router settings and the harddrive once but no resolution. Never faced this issue earlier. Any help?