AX760i suddenly shuts down and red light

Hi i have problem with ax760i. I first sent it to technical service but they said it has no problem. But after that i have still same problems with this psu. Now i will send this psu again but i dont know what will happen.



I have 4770K, MSI Z87 Mpower Max, Sapphire R280X Toxic, Corsair 750D case