I'm not quite sure what I did, but with the *Transparency > Alpha:* at 0.6, like **Img 1**, I was able to produce **Img 2**.

*Img 1:*

[![enter image description here][1]][1]

*Img 2:*

[![enter image description here][2]][2]

I used **Img 3**'s node setup and it started working. Suddenly, I could see the checker background behind the cube.

*Img 3:*

[![enter image description here][3]][3]

Here is the .blend file:

[<img src="http://blend-exchange.giantcowfilms.com/embedImage.png?bid=1497" />](http://blend-exchange.giantcowfilms.com/b/1497/)


  [1]: https://i.sstatic.net/SABIA.png
  [2]: https://i.sstatic.net/ZTrS1.png
  [3]: https://i.sstatic.net/BPOYb.png