Hello all! So I'm trying to check out the MK FC 2.5 in KopterTool. I hooked the FC up to the MKUSB and KopterTool talks to it just fine. I flashed the 2.04a firmware (was 2.02x). Loaded the Octo2 configuration. It seemed happy except for whining about missing BL-CTLs.. makes sense, they were't hooked up. Then a couple minutes later I connected the 5-wire molex cable between the FC and the double quadro xl 3.1 board. KopterTool reports an I2C error (no details). If I do not launch KopterTool, then the BL-CTL sends me 4 audible beeps ( "4 "E" = A doesn't go to high" according to the MK Wiki ). I'm using the 5V jumper to power this off the laptops USB 3 port. Do I have to power the BL-CTL with a lipo? How do you troubleshoot i2c errors? Thanks for you help! EDIT: I also do not have any of the motors hooked up, if that matters.