Replace a motherboard and see. However the number of pleas for help on your AMD system means it's not a system I will build or advise others to make. At under a year old it's surely in warranty.
My computer has run beautifully for half a year now. Last week, my computer wouldn't make it past post and the VGA LED was lit up on the motherboard. So, I took the card out and placed it in the second PCI x16 Slot on the motherboard, while moving my WLAN card to the newly empty slot. It ran flawlessly for about 4 more days. I tried turning my computer on last night and it would not start up again because the VGA LED was lit up again. Is it possible that my GPU is killing my PCI Slots? I just don't know where to go from here! All help is accepted.
CPU: AMD FX9590 8-core 4.7GHz
GPU: Sapphire Radeon HD 7990 6GB
PSU: Rosewill 1000W HIVE Bronze Series
Motherboard: ASUS Sabertooth 990FX R2.0
RAM: G.Skill Sniper 1866 (2x8GB)
CPU Cooler: Corsair h105 Liquid
SSD: Samsung 850 EVO 500GB
HDD: Western Digital 1TB
Case: NZXT Phantom 530