I have been playing around with my Arducopter for a month or two now and it has been performing well. However, since last week it has started yawing like crazy. It tilts while taking off and then starts spinning rapidly in the air. I have flied with and without SIMPLE in the STABILIZE mode. Here are the steps I have taken:
1) Tried Firmwares 2.3 and 2.5.3
2) Erased EEPROM, reset the board
3) Leveled the quad multiple times.
4) Calibrated the compass using the new Mission Planner with Live Data as well as with a tlog.
5) Ensured the power board is connected to the right ESCs and the right motors
6) Checked motors directions are correct
7) Motors are mounted securely and vertically on the arm
8) Made sure the center of mass is almost dead center
I am using the standard 3DR quadrotor frame. I initially suspected the magnetometer (compass) as the issue. However when I disable the compass and fly without SIMPLE it continues to yaw.
Any help would be greatly appreciated. I am losing my head over this issue.