I have the APM2 with 2.5.4 loaded in my hexacopter. Sometimes when powered on the APM2 will not go through its startup routine. It happends randomly. The blue solid LED instantly comes on and the leds do not go through the sequence. Nothing else happends. The red LED does not have any activity even when the gps gets a lock. Mavlink does not work either. I cleared the eprom, reloaded the firmware and still the same problem. I have sonar, xbees and a receiver connected. I have disconnected the sonar and xbees and repowered on and nothing. I never connect the usb and xbees at the same time btw. I think this problem started a couple days ago when I loded 2.5.4 All connections are tight. So basically what does it mean when the solid blue light comes instantly? If anybody has any ideas they would be appreciated.