When I power up my APM 2.5 board (via USB port) with no peripherals connected everything is fine. When I add the 3DR Radio the board still powers up correctly using the USB port. When I connect the Ublox LEA-6H board and then add power via USB, the the APM 2.5 board blinks once then goes dark. I am connecting the GPS via "old" style connection on the APM 2.5 board.
Can anyone offer any suggestions to troubleshoot this?