I strongly doubt your EX2 is defective. See this thread esp. points 1 & 2 → http://community.wd.com/t5/WD-My-Cloud-EX2/EX2-Install-and-Launch-Issues-The-Blinking-Yellow-Light/m-p/799573#M1352
Another tip…if you are a relatively tech-savvy person, you can skip installing any software and just use your browser to access http://wdmycloudex2 (assuming you are using a Windows computer - I think for Macs it gives out a different name which I can’t remember now). Once the dashboard comes up in your browser login (password is blank by default, userid is admin). Then get to the Settings tab and under Utilities sub-section look for the Format functionality. You should be able to then format both your drives from there. Once they are formatted the yellow blinking power light should change over to solid blue. In the 8 months I have had this device, I never once installed the software. The dashboard accessible through a browser has been sufficient for all my needs.
If this helps, please click the star under my username to the left of this post to give me a kudo.
