Where does this cable go?

I opened my iPad to replace the digitizer. After opening it, I noticed that one black cable directly on the right side of the home button was loose. For a better idea of what I'm talking about, see pics.

This cable is loose now and I can't figure out where it was attached.

Also, the iPad does not charge properly anmore. When I plug in the 30pin cable it doesn't recognize that it's being charged. Charging also takes awkwardly long (after 14 hours it got to ~51%) but as I already said, It does not show the charging symbols on the display.

The display on the other hand works perfectly fine. The iPad is still opened up.

Does anyone know where this cable belongs to? Or any other idea why it doesn't charge properly?

Thx in advance.