If you're having issues with the proximity sensor, ambient light sensor, or earpiece speaker on your iPhone 3GS or iPhone 3G, the proximity sensor cable may just be the actual culprit. Luckily, a proximity sensor cable is inexpensive and relatively easy to replace.
Disclaimer: As with any repair, iMore nor PXLFIX can be held responsible for any damage you may do to your device. It’s also worth considering that opening up your device to perform any repair or modification can and will void your Apple warranty. If you don’t feel comfortable opening your device, don’t. Use extreme care and caution when performing a repair on any device.
PXLFIX recommends using only quality and genuine parts from a reputable supplier like eTech Parts. They have quality parts, tools, and much more for all your repair needs.
This repair will be performed in exactly the same manner regardless whether you have an iPhone 3G or iPhone 3GS.
Before performing any repair or removing any screws or parts, always power off your device.
Using your #00 Phillips screwdriver, remove the 2 screws located on each side of the dock connector.
This part can be a bit tricky so please do this with extreme care so you don't tear any cables during the process.
The easiest way to remove the digitizer assembly is by using a suction cup.
Remove the cables that attach the digitizer assembly to the logic board:
Once you have the bottom of your digitizer assembly popped up we can remove the cables attaching it to the logic board.
At this point you can set the body of your iPhone aside and flip over the front screen assembly, which is what we'll be removing and replacing the proximity sensor cable on.
This step is optional and not required but I recommend it. Removing the LCD will allow you to get a better view of the induction flex you'll need to remove. It'll also give you more room to maneuver your pry tool around. If you don't remove the LCD, make sure you don't apply any pressure to it when removing the induction flex and speaker assembly.
We will need to remove the proximity sensor cable from the front assembly in order to put in the new one.
You'll notice that the proximity sensor cable is attached with some adhesive to the metal clip that holds it in place. To remove it, gently peel the cable off the metal clip. You'll notice dotted lines that are printed onto the cable to assist you in lining it up correctly when placing the new one onto the clip. If you need to, you may apply more adhesive. Your replacement cable may have come with adhesive pre-installed already.
Once you've replaced the proximity sensor cable, you'll just need to reassemble your iPhone by following these directions in exact reverse order. You can also watch the video above as it contains re-assembly instructions as well. As a side tip, take care to snap in the induction flex cable carefully. There's a clip towards the bottom you'll need to make sure snaps in all the way or you'll have issues putting the assembly back together.
That's it! You probably saved quite a bit compared to what it would cost to buy a new iPhone. While the cable name may sound scary, the process to fix it wasn't that bad, now was it?
If you do run into problems, make sure to check out our DIY and mod forums below. If you don't feel comfortable opening your device on your own, you can always contact PXLFIX about mail-in repairs as well.