Gigabyte GA-990XA-UD3 (brand new)
Ati radeon HD 4870 (~5years old)
AMD FX 8350 (new)
Kingston HyperX 1600MHz 2x 4Gb (new)
Corsair CX750M 750W PSU (new)
As you can see, all of the components are new (excluding the GPU). The HDD is old as well but I doubt that's at fault here. The problem arises when powering up: firstly there's no signal to the monitor. Second problem comes up after a while when the system restarts itself in a similar matter as pressing the reset button. This continues until the power is turned off.
I have tried switching the RAM sticks' position on the MOBO and switching the GPU between PCI x8 and X16 ports. I am at my wits end currently and could use some expertise on the matter.
Thank you in advance.