Hey all, Long story short, my P2 caught on fire and crashed. The preview: I blew out the cam/power aux cable port on the main circuit board (part 10) due to hooking up a go pro fpv cable incorrectly (Connected yellow Video to OSD, ground directly to TX). No big deal, I've swapped out main boards before. Well I swapped out the main board and was meticulous with my welds. It looked great. I put everything back together, tested, and flew. I made two test flights, it crashing on the second due to motor failure on the right rear motor. It flipped upside down and fell about 30 feet. Broke all 4 props, housing, melted receiver and am board. The video TX, gimbal, and camera was not installed or hooked up on both flights. Upon it crashing, I saw the right rear esc to main board connection had burned. My assumption is that it got so hot that the welds melted and then caught on fire. The question is, what would cause so much damage or initiate that kind of heat? Maybe the V or G wire came loose and touched something? Any ideas? I've bought all the parts to rebuild, but don't want this to happen again. I'm almost at the point where it wouldn't be worth rebuilding again if it crashes . I know I messed up, so only constructive criticism please.