No video when restart/reset

Hi all,

I've got a problem with (I think) my brand new motherboard. Every time I reboot the PC or press the reset button on my case, no more video output until I manually turn off and on the PSU. Everything else works perfectly and I have tried both Onboard and dedicated (HD 7870). Thanks

Specs: i5 4690, XFX 7870, 8gb Ram (1600), MSI Z87I GAMING AC

I have tried updating the bios - it flashed successfully however the problem still persists.