Hey, Just A Shot But I Have Noticed When I Plug In My Ps Cable My Usb Keyboard Lights And Mouse Reciever Led Come On For A Split Second,,and With My K8n Diamond Plus I Had The Same Problem You Are Having ,except After A Couple Of Days The Power Supply Would Not Come On At All, Also It Would Be A Good Idea To Have A Spare Ps For Youre Rig Anyway,,so During Rma You Still Have A Gamer To Use And Not To Just Look At,,well Best Of Luck!!!