iPhone 4: no Wifi and only works for a minute on Docking System

Hallo everyone,

I have a iPhone 4 which battery got swollen up while it was in the Sony Audio Docking System (RDP-M5iP). I replaced it with the Tutorial on this website but now it only turns on when it is plugged into the docking station (only for a minute or so until it restarts). I tried to charge it with the standard charging cable but that did not work. It was not even visible on PC when I tried to make a Back Up. Next I tried to make a BackUp to ICloud while it is plugged into the cocking station but the Wifi does not turn on. To be more precise the wifi option was gray.

I really hope someone can help me with this problem.
Thank You in Advance