Arduino Leonardo not connecting

I just got an Arduino Leonardo from adafruit and soldered on the data logger. When I went to connect it to my computer the green power light comes on then the orange L Led starts to flash. It doesn't appear as a com. I tried connecting it to my PC but it did the same thing. It doesn't show up as a usb connection on the system profiler. On the PC it didn't show up in the device manager.

Thanks for any help.

My arduino Uno works perfectly fine with both computers.

If anyone is having this problem I found that the wire I was using only provided power. Try a different cable

Thank you for the follow up.