Camera and Audiojack does not work, cannot Update

The main Camera and the Audiojack doesn't work anymore. I replaced the lcd and digitizer. Then returned to factory settings. Update to higher Android Versions result in bootloop.

So, why do the Audiojack and the Camera not work? Software or Hardware Problem?

I will Try to dissamble the Phone today. Maybe i forgot to plug in some cables. But why can i not update? OTA and adb/fastboot didn't work. Im running the nexus 4 on Android 4.2.2, would like to Upgrade to higher Versions.

Some hints anyone?