if u open the psu calculator and put the gtx 1070 it will told you that it need 29.2A on the +12 V cable
i see that your psu is 600w good for this gpu but it has 4 cables 12v 2 of them 18A and 2 others 20A
try to use the coverters that comes with the gtx 1070 to plug more than one cable 12V
and...