DX4e binding issues

[Smythcounty]

I recently bought a DX4e to use as a buddy box with my DX5e. After connecting the two it wouldn't work. Tried multiple cables. Then I tried to bind the DX4e to my ar600 in my apprentice to test the radio and I get a flashing orange light on my receiver and then when I try to bind the radio the orange light pauses for a sec and when I release the trainer button to complete the bind the light goes away. If I rebind to my DX5e it works flawlessly and I get my steady orange connection light. The DX4e was an eBay item that was used with a helicopter. Any ideas? I'm stumped. Thanks.