I'm running a x99-a/usb3.1 mobo and originally had 4x16gb vengeance lpx 64gb sticks that was giving me code 53 because unbeknownst to me it wasn't compatible with the board. Went out and purchased 8x8gb vengeance lpx 2166gb sticks (CMK64GX4M8A2133C13) which I've triple verified is on ASUS' compatibility list and still getting code 53. All the ram is clicked down and pushed in all the way on both sides (if I pushed any harder the mobo would probably crack). Any ideas on how I can trouble shoot the issue? Much appreciated.