Here the first lines of my serialport output after a fresh restart of the arduino:
i2cWcWrite failed: 2
i2cWrite failed: 2
i2cW 2
i2cWrite failed: 2
Post your code. The serial output seems failing too, might be a power problem.
After that it just goes on with the "i2cWrite failed: 2" message. What does the 2 mean?
It means the the I2C device is not answering to requests. This usually is the case if the connection is broken or if a wrong address is used.
I talked to the guys from Sparkfun. They are suspecting that due to the impact there could be a cold joint within the board and that i could try heating the board up with hot air to get the solder flowing... But I'am not so sure if a small impact like the robot falling over could have formed such a cold joint....
The cold joint must have been there before but it may be that the impact broke the little connection it had before. Cold joints often show some connection in the beginning but tend to loose connectivity suddenly. I would try Sparkfun's solution, this is not improbable.