Great to see there is a sub-forum for the Axe CP!

Here's the problem I have. Hope someone has an answer for it since I've never crashed my heli yet and I hope to keep it that way.
I seem to be having some issues with my tail rotor. How do you test to see if the motor or the e-board is starting to go bad. Everything has been flying great until yesterday. I would fly one battery, let it rest about 10 minutes, then about half way through my second battery, the tail keeps wanting to spin around counter-clockwise. If I continue, it gets worse. This has happened twice. Could the motor be going bad or is there an issue with the e-board or something else, and, how do I test all of these components to find out which I need to change out. I've been flying for about 3 weeks without any issues until now. Any info would be most appreciated. Thanks in advance.