Front camera issue, how to recognize logicboard damage

Hi there,

I have a question regarding the front facing camera of a iPhone 4. I replaced the screen on a iPhone 4, and now the front camera is having problems. Now i found some info about soldering a jumper above the headhphone jack connector. But my question is, how is this part supposed to look like.

The reason i'm asking is the following:

in the guide of iFixit you see this picture:

logic board connectors

The part we are looking for are the two small contact points just above the most left smal connectors. (headhhone)

It is suggested to create a jumper here is this part is missing, now on this picture i dont see these point make contact, is it broken here?

I also see this picture popping up at several websites, Front camera connection points

Has there been some soldering already going on here?

So what i like to know, when do i know that i have to jump these contact points. The second picture look more like its already been soldered. On the picture of iFixit i dont see any part at these connection points...