I recently bought a second hand iPhone 3GS and the phone was in good condition, all the buttons worked apart from one. The power button on the top did not work reliably and consistently. This made it difficult to turn the phone off as holding it in for a few seconds did not work. Also pressing it briefly to turn the phone on or off did not work very often.
Investigation online showed that this was due to a damaged switch inside the phone. Being an electronics engineer I thought I would have a go at replacing the loom. This is what the replacement 3GS loom looks like :
|Replacement 3GS loom with Headphone, Power, Volume and silent switches|
I managed to find a very detailed step by step video that shows you how to disassemble an iPhone 3GS right down to the loom that we need to replace. And I really do mean detailed, screw by screw.
You can pretty much get any replacement part for your iPhone from Amazon, the loom for Headphone, Power, Volume and mute switches, The back casing, the home button, the front glass and batteries too :
These iPhone looms are available on ebay for as little as £2.49 I paid £3.50 for a new loom from a seller in Derby as it happens. Its worth looking around as you could pay over the odds for the very same thing. Click HERE to search for 3GS looms on ebayUK.
The loom is flat when you get it, You will have to fold it to match the original one in the iPhone. It has little strips of self adhesive tape on bits of the flex. You will need to peel off the white bits.
The step by step video on removing a faulty 3GS loom:
The major problem with this video is that it does NOT show you how to reassemble your iPhone and how to install the replacement loom. It just says reverse the procedure, Yea right !!!
Some other things I would suggest. When you open the phone up you will find its full of dust and other debris. Its best to try and remove all of this before you assemble the phone otherwise these bits may end up in the camera housing area and impair the cameras view. I used cotton buds soaked in Isopropyl alcohol and also a little can of air.
My tips to help you do this:
1) You must have tons of patience, this is a very complex process to follow.
2) Allow plenty of time to take it apart and put it back together. Don't rush it.
3) You will need a clean tidy, well lit desk to do this. It's not the kind of job you should attempt on your knee or on soft furnishings as the screws in the iPhone are so tiny you won't find them ever again if you drop them.
4) You must have the right screwdriver size, do not bodge it
5) I suggest you magnetize your screwdriver, I found it impossible to assemble it without doing this.
6) In order to make sure you do not forget any screws during the reassembly of the phone what I did was get an A4 bit of paper and stuck bits of Blutak on it so I could stick the screws into it as I removed them. I then wrote next to them helpful things such as "Step 5 - 8 x screws and camera clamp". The BluTak will stop them rolling around and the notes will help you put the phone back together in reverse.
7) I found it handy to stick the back of the iPhone down onto the desk using 4 balls of BluTak, this made it easy to fit the screws back in without having to hold the phone.
8) Use a movable table lamp to illuminate closely what your working on, ideally day light.
9) The battery in my phone was stuck down so was not removable like the one in this video. I had to carefully prize it off the back panel slowly bit by bit.
10) Do not use excessive force on the connections, look at the mating parts and understand how they fit together.
11) The view at 3:49 is of the top of the phone where the power button is.
12) When removing the 8 screws that hold the motherboard in place, one of the screws near the camera has a little spring bracket that holds the camera down.
13) In Step 8 be aware there is a small springy tag on the edge of the board near the antenna that will make it hard to pull the board out.
14) In Step 10 there are a few different lengths of screws, make a note on your paper which goes where.
15) When fitting the new headphone socket you will have to fold the ribbon flex around the moulding. On the original one you will notice that it has clear insulating tape covering the components that are on the side of it. The replacement one does not have this so you will need to insert a tiny bit of paper down this bit to stop it shorting on the metal work near that corner otherwise you may find problems with your sound.
16) If the power button falls out and you are wondering how it fits back in. That odd metal bar thing (looks like a toilet roll holder) should be down and fits into the area below the button. It is there to provide a stability to the long power button so it does not wobble when you press it.
17) The small screwdriver I used was in a set of "jewelers screwdrivers" I got from Poundland.
18) If you damage anything when putting it back together you can always get spare parts for iPhone 3GS from Amazon.
Its worth pointing out that I did NOT have a suction removal tool, What I used was a big lump of BluTak which I mounded onto the glass near the home button I then grabbed hold of it and this worked perfectly. Probably would not work if it had a screen protector stuck on it.
After I reassembled the iPhone I was expecting it to not work at all or for something not to be quite right, but amazingly everything is fully working. And the power button is now perfectly reliable. So there you go fully fixed for a total of £3.59 for the loom and about 2 hours of time.
Testing that you have reassembled the iPhone 3GS correctly.
After such a fiddly process you are bound to make mistakes and not connect something correctly so its important to check everything before your 100% happy with the repair, especially if you have done this repair for someone else. After all you don't want to hand it back and then they come back to you a week later saying the Mapping no longer works.
Things to check after repair :
1) LCD missing lines. Are all the pixels on the display still working ok.
2) LCD Backlight, Is this working ok
3) Home button, try it several times.
4) Power button, try it several times by pressing briefly then try power off mode by holding it in for 4 seconds.
5) Volume buttons, play some music and try up and down several times.
6) Mute/Silent switch. Toggle this down and ensure the bell with a slash through it shows. toggle it up and ensure the bell with volume bargraph shows. Try several times.
7) Plug in some iPhone headphones and check left and right speakers are working ok.
8) Make a phone call and check that the microphone built into the headphone lead works ok.
9) Proximity sensor - Make a phone call then using your hand cover up the top face of the phone (where the earpiece is) and ensure that the backlight goes off. This checks you have plugged in the little ribbon correctly.
10) Click on the Maps app and tap the location button (bottom left), ensure that the GPS is working by the map moving to where you are.
11) Ensure that Wi-Fi is working by using the internet via your wifi connection.
12) Connect the iPhone USB lead and ensure that the iPhone starts to charge up ok.
Hope this helps you if your contemplating doing this. If you found my guide of use then please comment or link to it from Facebook etc.
Follow me on Twitter - Andy Savage from Derby.