How to fix the dock connector on an AT&T/GSM iPhone 4

A dock connector can go bad over time or if it's become exposed to liquid or humidity. If you're off warranty and would rather attempt a DIY repair instead of shelling out the cash for a new iPhone, here's how you can fix it!

Disclaimer: As with any repair, iMore cannot 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.

Read this first

If your iPhone 4 recognizes a charger but dies when you disconnect it, odds are the battery needs to be replaced, not the dock connector. We can help you replace your battery too:

What you need for a DIY GSM iPhone 4 dock connector replacement

iMore recommends using only quality and genuine parts from a reputable supplier like iFixYouri. They have quality parts, tools, and much more for all your repair needs.

  • Replacement dock connector
  • 5-point security screwdriver
  • Standard #000 Phillips screwdriver
  • Spudger tool
  • Razor blade
  • iSesamo Opening tool (not necessary but awesome for prying up cables and getting under adhesive)

Power off your iPhone 4

iPhone slide to power off

Before performing any repair, always power off your device before removing any screws or parts.

Remove the back

Remove the dock connector screws on your CDMA iPhone 4

  1. First remove the bottom 2 dock connector screws in your iPhone 4. Use either your #00 screwdriver or the five point depending on whether or not your iPhone 4 has security screws in the dock connector. Almost all newer devices will have security screws.

Remove the back of your CDMA iPhone 4

  1. To remove the back simply slide the back upwards and lift it off gently.
  2. Set the back and 2 dock connector screws aside.

Remove your SIM card

Use a SIM removal tool or a paperclip to remove your SIM card and tray. Set them aside.

Remove the battery

Remove battery screw iPhone 4 CDMA

  1. To remove the battery you'll need to remove the #00 screw holding the battery clip in place. Remove this screw located to the bottom left of the battery.

Remove battery clip iPhone 4 CDMA

  1. The metal clip on the battery is what clips the battery to the logic board. You'll need to pop this clip up with your plastic pry tool. Simply stick the end of your pry tool underneath the clip and gently pull upwards until it unfastens from the logic board.

Remove battery iPhone 4 CDMA

  1. To remove the battery, I do not recommend using the plastic pull tab. There is quite a bit of adhesive underneath the battery and the tab will normally just rip off or you can bend the battery. Instead, run your pry tool along the right side of the battery and break the adhesive that way. Once the battery is free from the adhesive, you can pull the battery out of the phone. There are no other connectors holding it in.

Fold over battery tab on iPhone 4

  1. You will notice a tiny grounding clip sitting underneath where you unscrewed the battery. Set this aside for replacement during reassembly. This is a grounding clip for your antenna. Make sure you put it back in place before reconnecting your battery.

Remove the dock connector shield and disconnect the cable

Remove dock connector shield iPhone 4 CDMA

  1. There is a shield held on with two screws covering the dock connector cable. Remove the two screws holding it in place and set the shield and screws aside, remembering where they came from.

Remove dock connector cable iPhone 4 CDMA

  1. Next, use your pry tool to pry up the actual dock connector cable. Be careful as there is adhesive holding the cable in place as well. Peel back the adhesive gently to free the cable.

Remove the top logic board shield

  1. There are 5 screws holding the logic board shield in place. Remove the 5 screws holding it in place. Just be sure to remember which holes they came out of as the screws are different sizes. I always keep them in order of how they came out.

  1. Next you'll need to remove the shield. There is a tiny clip built into the shield holding it in place. (Refer to the photo above.) Pop it up with your pry tool and you should be able to slide the shield up fairly easily. Just take care not to bend it or break off a clip.

Disconnect the 6 cables from the top of the logic board

  1. There is only one connector holding the camera to the logic board. Remove this cable in the picture above using your pry tool. Gently lift upwards and it will pop right off.

  1. Next gently lift the camera out of the device. You'll notice there is a tiny tab that is seated underneath the LCD and digitizer cables to the right.
  2. Next pop up the LCD and digitizer cables to the right of where the camera cable was connected. You pop them up in the same direction.
  3. The 3 cables further to the right will need to be disconnected as well. They pop up in the opposite direction.

Disconnect the cellular antenna

iPhone-4-GSM-cellular-antenna-removal

To disconnect the cellular antenna, just pop the round cable up from the logic board holding it in place. It is connected to the speaker housing so just leave it where it is for now.

Remove the logic board

  1. Start with the 2 screws holding the logic board down in the middle and at the bottom left. Both use your #00 Phillips screwdriver. They are the same size. The one on the right of the logic board in the middle of the device has a water sensor over it you'll need to remove.
  2. The second screw is located where the logic board meets the speaker assembly towards the bottom left of the device.
  3. The third and final screw holding the logic board in is located at the top of the logic board off to the right. It is the only cross-head screw in your device. Use a small flathead screwdriver to carefully remove it.

iPhone-4-GSM-logic-board-removal

  1. You should now be able to remove your logic board. Holding it at the bottom, gently pull it upwards. I use my other hand to lift up at the top where the rear facing camera used to be.

Logic board grounding clip iPhone 4 CDMA

  1. Take note that there is a small rubber piece that sits at the top of the logic board. You will need this for re-assembly so make sure it doesn't fall off. If you lose this, you could see reception issues.

Remove the speaker assembly

Remove the speaker assembly CDMA iPhone 4

  1. To remove the speaker assembly you have one more #00 screw to remove. It sits to the right of the speaker assembly in the bottom right hand corner of your device. Remove it.
  2. The second screw holding the speaker assembly into your iPhone you've already removed when you removed the logic board.
  3. Gently lift the speaker assembly out of your device and set it aside.

Disconnect the home button

  1. The home button fastens into your dock connector so in order to replace the dock connector assembly we'll need to unplug the home button.
  2. Use your pry tool to gently unfasten the clip holding the home button cable in place. This cable is very tiny and fragile so handle it with care.

  1. Next, gently use your pry tool and your finger to back the cable out of the clip.

This is as far as we'll need to go with the home button. Once it is unhooked, just disregard it while we move on to the dock connector.

Remove the dock connector assembly

There are two screws and some adhesive holding the dock connector into your iPhone 4. We'll need to remove those in order to pull the assembly out of the phone.

  1. Remove the two screws holding the dock connector in place with your #00 screwdriver. There is one to the left and one to the right of the actual docking port. The one to the left may be covered with yellow tape. Just peel it back.

  1. The left and right sides of the cable are held down with adhesive. Use your pry tool to pull up the cable and the left part of the assembly. Take care not to pry on the home button cable. Use your pry tool to hold it out of the way when removing the dock connector assembly from your iPhone 4.

  1. Next move over to the actual dock connector cable which is also held in with just adhesive. Gently pry it up.

  1. The rubber gasket to the left just plugs right into the frame, so to speak, so just pull it out gently to separate it from the frame.
  2. You should now be able to remove the dock connector assembly from your iPhone.
  3. Now pull the rubber gasket from two steps ago off the old dock connector assembly as you'll need to place it on the new one.

Install the new dock connector assembly

  1. Place the rubber gasket you removed from the old assembly onto the new one and now we're ready to install the new one.
  2. Peel the adhesive off the back of the new dock connector. Compare where the adhesive is on the old and new assemblies. Your iPhone 4 has grooves in the frame showing you where to line up the left and right.
  3. First line up the actual dock port and sit it flush. Replace the 2 screws on either side to hold it in firmly.
  4. Before going any further, go ahead and stick a dock connector cable into the port like you would to charge your iPhone. If it slides in nicely and feels like it should, continue reassembly. If it doesn't, remove the 2 screws and re-align it. It can be a bit tricky to line it up perfectly, but you'll get there.
  5. Plug the rubber gasket back into the mid-frame.
  6. Now line up the rest of the dock connector cable assembly. Make folds in the cable where necessary. It's helpful to compare how your old cable is folded and mimic those folds on the new one. Be careful not to dislodge or tear the home button cable while re-positioning the dock connector.

Re-connect your home button

How to unfasten the home button in a Verizon or Sprint iPhone 4

  1. Use your pry tool and finger to carefully slide your home button cable back in place.
  2. Once the cable is positioned where it should be you can go ahead and use your pry tool to push down the clip that fastens it in place.

Reassemble your iPhone

Once you've gotten your dock connector in nice and flush, you're ready for reassembly. You can either follow these steps in reverse order or watch our reassembly video above starting at about 3:20.

And... done!

Upon powering back up your iPhone, check to make sure it'll hold a charge. If the dock connector was installed correctly you should be back to being able to charge normally.

Allyson Kazmucha

iMore senior editor from 2011 to 2015.