I'm working with 2 high school students for their physics class.  They learn soldering as part of the class and we are building quadcopters for the lesson.
Yesterday they both got their flight controllers powered.  Both are using the same setup with a Flip32 FC.  On power, they both show the same light patterns, but only 1 of them beeps.  The other is completely silent.  
Is this normal?  Something I should worry about?  So far the only thing connected is Lipo to PDB, PDB to FC via 5v pad.

I won't have access to them again for a few weeks but I'm hoping I can make sure there isn't a problem before going back to the class.

Beep? you mean you have a buzzer attached on both of them?
I think if you connect the boards to computer, and the 3D model is moving as they should in the GUI then you should be fine.

The Flip32 (and Naze32 rev5) make a series of beeps on power. They are status beeps (I know because I once fried a Flip32 and the beep pattern changed).

No buzzer attached, but it sounds similar to that (just quieter).