Common iPhone 3G and 3GS repair issues
1. Most common
Broken or cracked glass - By far the most common repair issue for the iPhone 3G and 3GS is a cracked digitizer and glass assembly. The glass panel that you touch to activate the iPhone has a touch sensor(digitizer) adhered to the back of it. When the glass gets cracked, even if the touch sensor is still working, you will need to replace both the digitizer and glass because you cannot remove and reattach the digitizer without damaging it. We only sell the glass with the digitizer attached. They need to be assembled in a dust free environment(cleanroom). There are also a few options to consider when replacing your glass. We at eTech Parts, have multiple parts that will fix cracked glass:
Glass and digitizer only - The cheapest but also the most difficult to install. You have to remove all the broken glass from your plastic digitizer frame and install the new glass into your frame and reinstall the LCD Screen.
Glass, Digitizer and Frame Assembly - A little more expensive but much easier to install. This part has the digitizer and glass already installed in a new frame with home button and ear speaker. Simply swap the lcd screen over from your broken unit.
Glass, Digitizer, Frame and LCD Assembly - The most expensive option and the easiest to install. This is the complete assembly so its very simple. Simply remove your broken assembly and install this new one.
2. Broken LCD Screen - Sometimes the glass and screen will both break and sometimes the lcd screen can get broken and the glass stays in tact. The LCD screen is fairly easy to install. If you cant see a portion of the screen, have lines in the screen or the screen is all gray, This is most likely the part you need.
3. Charging Port Assembly - If you set your phone down in liquid and just the bottom of the phone got wet or you have an issue with your microphone or external speaker or have a damaged dock connector, chances are this is the part that will fix your problem. We sell just the board or the entire assembly. Its worth the extra money for the assembly because the speaker and microphone are soldered on.
4. Defective home button - Usually if the home button is not working its due to broken pins that connect it to the charging port board. You can look at it and see if these pins are broken. It can also be caused by a defective charging port board(see above). If you have broken pins on your home button then you can replace the home button but you will have to remove the glass and digitizer assembly to get to it. For an easier, but more expensive route, buy the glass, digitizer and frame assembly. It has a new home button already installed.
5. Defective Headphone Jack Assembly - This assembly controls your silent switch, volume switch and power button. It also has the port where you insert your headphones. If you have a problem related to any of these issues, chances are this part will fix the problem. Be warned, even for iPhone Repair shops this part takes a while to install and you have to remove the main logic board to get to it. Take your time and keep track of where all the tiny screws go and in which order they get reinstalled.
The above text is copyright eTech Parts.