Scotty,
Our airport express still drops out every now and then.  Whenever it does, my Mac doesn't see it.  I have to utilize airport utility or network preferences and that seems to somehow make it work again.  Do you have any clue as to why this happens?  Do you have any tips on how to make it stop happening?
Thanks,
___________

I've had several reports of the 7.5.2 airport device update causing the problem.  You (or son) could try downgrading the firmware. Here’s how:

1. Select Upload firmware from the menu bar in Airport Utility.



2. Choose the version you want to downgrade to from the pull down then hit ok. You’ll probably want to do this with each device on your network.



I can’t guarantee that will solve the problem. It could just be a bad airport express. But those are rare.