Please provide more information. What steps other than replacing cables have you tried? Who is your broadband provider? Do the My Cloud network port LED’s (both of them) light up and blink?
If your broadband provider is AT&T there is a problem with certain AT&T broadband routers. The workaround until AT&T fixes the issue is to connect the My Cloud to a switch or hub first then connect that switch or hub to the AT&T router. See the following thread for more information.
https://community.wd.com/t/cant-connect-my-cloud-using-att-uverse-1gig-fiber-service/140412
