My phone stop charging when I plug it. The first message I got was "This accessory may not be supported" This means that the USB cable is not recognized by the phone because either the USB is not working or the dock connector is not working. I changed the battery first but this didn't solve the problem. Then I decided to change the dock connector. I bought a cheap one from the ebay. It solved the charging problem but the microphone stop working and people can't hear me when I make a call unless I used the speaker. Then I re-installed the original parts to know what is the problem, and I figured out that the part that I bought wasn't good. My friend Mitch told me that ifixit have a good part so I order the dock connector from them, I got the package on time and I installed my new part and it works very good and it was easy to fit it in its place. The one that I bought it from the ebay has larger dimensions than it should be and in order to install it you have to use force which is not recommended.
I would like here to correct some information posted on the internet regarding the microphone in the iPhone 4 (may be this works with other versions), iPhone 4 has two microphones, one is near the dock connector (works if you don't use loudspeaker) and another beside the headphone port at the top (works if you talk with speaker). If you have a problem with the microphone (first mentioned), the dock connector should be changed because it is a part from the dock connector.
With the guides from ifixit.com, everything is easy to fix.
-iPhone is expensive and sensitive device, never buy cheap parts that you don't trust. The problem in buying these cheap parts is the risk of damaging your phone especially the logic board. Also, good repairing parts make it easy to figure out the problem, for example, when I installed the bad part, I thought that I damaged some other parts by mistake so number or possible causes increases which make it hard to make troubleshooting and you may buy additional (new) parts that you don't need.
- never repair or remove the cover for the phone while it is ON.
- It is very helpful to make labels for the small screws so that you know where you should put everyone in its place. They are very small and different sizes, if you insert any of them in the wrong place, you might damage the threads on the screw itself or the on the hole.
- Be patient and never used force more than required.