Running APM 2.8 Arducopter V3.2.1
Everything was running fine until a moter started running rough and caused a small crash, so I replaced all 4 motors. Then I thought it looked like they weren't all spinning at once so I decided to recalibrate the ESCs.
After ESC Re-calibration I have bad compass health and it won't arm.
I disabled all the pre-arm checks and it still won't arm.
I can re-calibrate the esc's and get the motors to spin fine after calibration.
I have no idea where to look for the problem. Please help.