MacBook won't turn on after replacing the Optical drive with an SSD

Hi Guys,

So here's my issue.

I decided to upgrade my macbook, so i replaced the optical drive with an SSD drive. However afterwards the macbook refuses to boot. It won't turn on at all. When i connect the power cable it just stays green.

I followed the guide and i don't think i damaged any cables. Visually all the cables look fine. I double checked the cables, I've also disconnect them and reconnect them just in case something was loose, but still nothing. I've disconnected the battery for half an hour and then tried again but still nothing.