BN220 not working when connected to CC3D Revolution

Hi everybody,
I’m new here so a lot of help is needed… thanks.

My problem is when i try to use a BN220 GPS receiver with the flexi port of the CC3D Revolution, the gps works fine when connected to my pc using a ttl/usb converter but when connected to the flexi port i can’t get even a led (on the BN220) blinking…

Checked the voltages with a digital mutlimeter and the Vcc from the flexi port is correct when nothing is connected but when i connect the gps the Vcc drops to 0.6V so it can’t work…

any idea of what’s going on?