Fans issue geeetech i3x printer

[shadowcaster]

Hi. I bought the printer in the subject and after many problems in assembling i have a issue with fans..the two fans didn't work. I tried to start those by repeater host but nothing. I tried in different plug on the mother board, fan1 fan2 fan3 and pwm. But nothing...if i power it with external 12V the fans work properly but not if i try to power by mother board. What i have to do?