I've answered this on a few other threads already but since it's here.
If the wrong motor type was chosen, the Rx8 will not arm.
It could have been either a bad solder joint but judging by the pictures alone this doesn't appear to be the case.
Hard to say much more without seeing it. But like I said in the other thread, we will stand behind our products and make it right.
Contact me and we'll take care of it:
support@teamtekin.com or
Rpike@teamtekin.com