Chosen Solution
So I replaced the digitizer on my phone and ever since the wifi signal has been absolutely poor. Does anybody know what may cause this or if I might of messed up a part doing it.
You have done one of two things wrong. Either you have had this tiny part fall off and you did not know where to put it.
It goes here
Or you did not use the correct length screw in this hole. The longest screw within the iPhone goes here. Also the oil from your fingers can affect Wi-Fi signal strength. So clean all contact points with Isopropyl alcohol. Revision To show you which screw is in fact correct I have edited an image of the whole set of screws within an iPhone 4. Complete original set of screws.
Shown here is the screw that I originally said was the correct screw. In fact I was wrong.
Here is the actual screw required. Please note that it has a smaller head diameter.
Where does that squiggley black piece go?
It goes on top, above the battery, near the camera:
