I've done the "Record Arm" deal more than once (as in forgot to arm the Track and/or the Transport). I also fully understand the getting the IRE of the other half up also. Track I/O's can get you all flustered sometimes. I have 2 computers that are almost identical to each other that I have Pro Tools on and both should work identically but one always gives me grief, don't know why, but it does. So, I brought the problem one (this one) home and just use it here. Once you get PT up and running, find what's causing no audio, hopefully, it will be just a simple overlook.