Q: AirPort Express´s Light Green, but no Internet

Hi! The APExpress is connected here with TimeCapsule, and it is supposed to make a broader wifi network here.

It works alright if there´s no cabe plugged in it, but I want also to use it far from the TC, so I have to wire the little box.

Now I have an AirPort Express which light is green, indicating internet access, but it doesn´t even appear in AiporUtility.

What should I do? I´ve tried a hard reset, pushing the small button while powering the unit, but it remains invisible, and has no internet available.

Thanks a lot for your time, and attention.