Process of elimination is best in this scenario. First and easiest is to try the transmitter with another plane, do the same same test, and see where you get. Then start eliminating things on the plane itself...servo by servo if you have to.
You dont really state the symptoms though, such as severe glitching, outright loss of signal, intermittent loss of signal, etc.. Maybe a bit of info in that area might help someone here to diagnose.
I can tell you, Futaba is $15 to inspect a reciever, and well.....if it's new.......your probably under warranty too. You might well even think about putting it in a less expensive plane before flying it in your new "pride and joy".
Don't take any chances though, sounds like you've got a beautiful plane there.