What gives what a pain took out my old Corsair HX750 put the G3 750 in and it won't even post. Pretty sure all the connections were right you can't really mess that up. Checked the connections everything powers on but it won't load windows or goto the UEFI screen let alone post a beep? Hate to send this back if I knew what was going on I think it might have something to do with the MB cable maybe because the CPU cable the give you two of those and i changed them both out. If I can't figure it out I'll exchange it for a Corsair...kinda liked the smaller size of this knocked off two inches when it's on the bottom.