Ram Slot 1 not working

Ok guys i have an issue and need some advice. I'm using an 17 2600k on an Asus Maxiumus IV Gene z/Gen 3 ROG edition mobo.

I had this PC built for me, and ever since i got it, i've been using 2x4GB of 1600mhz dual channel DDR3 Ripjaws, in channel A (Slots 2 & 4). Recently i decided to put another 2x4GB in channel B (Slots 1 & 3). Now whenever i put ram in slot 1, My PC will not post. It boots up for a second, then restarts with just the fans and case lights running. The PC will post with ram in slots 2, 3 & 4 though.

So what do you guys think it could be? faulty socket? Bent CPU Socket pins? Bad memory controller?

I forgot to add, my PC is running a loop, so it would be a pain in the ass to drain it just to look at the socket pins, my only worry are that if some are bent, the long term affects that may have on my PC.