No reception (stuck searching...) and interenet not working

I replaced my battery and power/volume cable while following the guide and video.

When I finished re-assembling the phone while making sure everything is connected as it should (cables and screws) I powered my phone on and found out that now I can't connect to the internet (altough it does find the wifi signal) and that it can't find any signal (stuck on searching...).

when I powered my iPhone on it also prompted me that facebook cannot verify the identity of webdev.facebook.com and after that I got another prompt for some other site.

I'm 100% sure that I havn't damaged anything, and I'm almost 100% i connected all the cables back to place and correctly (the not 100% part is for correctly, something has to be wrong here right?).

while taking these pictures I lost one screw (last picture) :(

please help!