hi all, i have 5 x 1.15y boards. i tested all boards one by one and they work. when i plug 2, the PSU shuts down.
PSU is a 650 W / 12V / 20A

 i tested each board with different cables, each board with its own cables and worked

any help is apreciated

PSU i use is : http://www.dc-shop.ro/surse/sursa-segotep-raynor-power-650w-l/