Me and my Dad flew our blade cx for the first time today and when my dad flew it he was near the ground and all of the sudden the blade cx's tail went up and it fliped and hit the rotors but nothing broke. We thought it ran out of charge and was acting wierd but we recharged the battery pack and the engine that spins the top rotor spins at a slow speed when you plug the battery pack in and doesnt change speed. I was wondering if it needs some serious fixing up or if its a simple problem? It didnt seem to crash hard enough to brake anything so i was wondering if something was wrong with it?

You can switch the wires of the motors to find out if its a problem with the motor, or possibly a 4-in-1 problem.

If your throttle was turned up when the blades hit the ground you may have suffered a failed 4-n-1. Take your CX to a hobby shop that has a demostrator CX and see if they will swap 4-n-1 units to see if that is what the problem is. As you probably know, the 4-n-1 is the most expensive part in the CX. []

Try what Gonwee suggested first. Theres a few things you can check before you need to worry about the 4 in 1. If your motors were on after you hit the ground you might have burnt a motor as well. These are cheap motors and will burn quite easily too.

Rotate both rotors and see if they feel like they rotate with the same smoothness. If 1 rotor seems a lot more tighter than the other , then you start checking things like gear mesh, look for bent shafts etc.

But check your motors 1st, then check for smoothness and let us know what you find and Im sure with all the experience in this forum someone will be able to help you.

You mean the rotor starts turning immediately after you plug in the battery, even before the 4 in 1 has armed? If so, then yes, the 4 in 1 has a shorted mosFET I'm sad to say