Which of the three Mainboard-Connectors is for the Touch-Sensor?

After disassembling my 8 gig 1st Gen iPhone in order to replace the broken glass and digitizer I found my Touch-Sensor not working anymore.

So I redid the whole procedure and it worked without a glitch, for about 3 hours...

Since everything besides the touch-recognition works I think it might be a faulty connection from the digitzier to the logicboard.

Does anybody know which one of the mainboard-connectors is responsible for what task? I named the connectors as follows ;)

• the one on the side of dock-connector (with the black clamp)
• the really annoying small one on the camera-side
• the bigger one on the side of the camera.

Thank you very much for your help!