As indicated above, did you try plugging the My Cloud direct to a computer’s networking port? If so what happened?
There is a KNOWN issue with at least one broadband provider (AT&T Uverse) where the My Cloud doesn’t play nice with the broadband provider’s router. The solution in that case is to put a switch in between the My Cloud and the broadband provider’s router. By connecting the My Cloud direct to your computers Ethernet networking port you can try to narrow down if it really is a bad port on the My Cloud.