My cloud will not connect to Router

[cpt_paranoia]

Just for completeness, this is almost certainly another autonegotiation problem between router and MyCloud Ethernet devices. See this thread for details and workaround:

Can't connect My Cloud Using ATT Uverse 1Gig Fiber Service

Flashing white is likely to be disk doing fsck; did you shut it down from the dashboard, or just pull the power? Flashing yellow is failure to find network; what are the Ethernet LEDs doing? Have you tried all ports on the router?