Just got my EVGA GTX 1070 FTW installed.  DOwnloaded Precision XOC.  When I click EVGA Logo LED the light (red color) inside the card lights up but not the logo? 

Yeap I can change colors.  Looking online it looks like the EVGA GEFOCE GTX 1070 side tab should light up too but it doesnt.  
 

Someone once reported here in the forum the same issue.
It ended up being the led plug that wasn't sitting correctly in the plug.

Yeah you'll have to the the backplate off I can't remember if you have to take the heatsink off or not to access that led cable
i did the thermal pad mod myself on that same exact card. It's not hard to take apart at all and just check to make sure the led cable is full seated you might need some thermal grease depending on whether you have to take the heatsink off or not.

just need to remove the 4 screws around the GPU, and the heatsink will be free to remove (need to remove a few plugs from the fans and the LED). No need to take the backplate off.