Moved WDMYCloud 2TB to decorate now won't connect to router

Hi, looking for some help…
I powered down (removed power connection) to my 2yr old WDMYCloud that (up till now) has been performing brilliantly, in order to decorate the room that contains both the device and my router.
The router I powered back up instantly in another room whilst I decorated but I left the WDMYCloud powered down for a few days as I didn’t need it straight away.
Anyway, job done router and WDMYCloud back in room, connected via ethernet to the router and I now have a solid yellow light at the front.
The ethernet lights are: top light, pulsing, bottom light off. The router has both lights flashing.
It appears to me that the router is trying to communicate but the WD is not having any of it.
I have performed a 4 sec and 40 sec reboot (ensuring I followed previous posts correctly as to how to perform it properly) still no joy
I have also tried to connect it to my windows8 PC, but still no solid blue light.
Any thoughts, it feels like the WD network card has failed… I am just praying that I have not lost any of my data!!!
Please help if you can- I will try anything at this stage!

nb: It is a sky router, no hardware has been replaced and no software updates performed over the last few days.
All other router functions appear to be working normally - admin page indicate all other devices are connected via the wireless

Obvious things to try:

different router port
different ethernet cable

Other possible failures for a power cycle failure are that the PSU is faulty, and unable to provide the startup current.

But the network interface failure isn’t that uncommon. The HDD may still be good, in which case, you can recover the data:

Many thanks for the response and the history thread. I have tried the obvious things.
Tech Support confirms it is likely to be a ‘unit failure’
I will test the power output of the PSU just in case, but I suspect as you do, that it is the network I/F.
I read that the disk system on the WDMyCloud devices are linux based, will a Mac be able to read it if i get a SATA to USB connection?