What is the model for your Seasonic 650W PSU? You should ideally list your specs like so:
CPU: i5 4670 4th
Motherboard: Asus b85 1150
Ram: 8gb ddr3 1333
SSD/HDD: 1TB Seagate Barracuda
GPU: R9 290x OC edition
PSU: corsiar VS550 this is the real one
Chassis: cooler master elite
OS: window 10
We're also going to need to know how old the PSU is and if you were experiencing the problem earlier...? Have you tried powering off the iGPU? You should also include the series for your i5 processor.