Q500 4K. The original issue was Just a burnt out esc, replaced it. cut it all on and the board went up with a puff of smoke two pieces on the back and one on the front are clearly burnt. Replacement was bought from a reputable vendor and had been tested and worked. Yes I’ve used the GUI before. It always connects, but it seems to be hanging on the Trying com3. How do you assign motors without powering on the unit? The motors are connected the way my original board had them soldered. I’ve replaced my airframe several times and had no problems after soldering everything and connecting it back. I was thinking I may have not connected the other wires right. The compass(black) connects on the board under the esc(orange brown)and gps connections? And the antenna wire plugs into the GUI pigtail which plugs into the set coming off of the board.