iPhone 4 (GSM and CDMA) Troubleshooting

Oh no! Your iPhone's glass did not survive your unintentional drop test!

Take a deep breath and see if your iPhone will turn on and operate normally. In most cases, the iPhone is still functional but now a cosmetic disaster. Unfortunately, the iPhone 4's front glass and LCD are fused together and must be replaced as one piece.

The display assemblies differ between carriers, so a CDMA iPhone 4's display assembly is not compatible with a GSM iPhone 4, and vice versa. Luckily for you, we have parts and guides for both the GSM (AT&T) and CDMA (Verizon) iPhone 4's.

Apple did not grace the rear panel of the iPhone 4 with the same high-strength glass as the front, so fractures are much easier to come by on the backside. Even though the CDMA and GSM versions of the iPhone 4 have different parts, the procedure to replace the rear panel is the same for both models. GSM iPhone 4 owners may choose between either an OEM replacement panel or our transparent rear panel. A high quality OEM replacement rear panel is still available for CDMA iPhone 4's.

Even after furious button mashing and screen smashing, your iPhone 4 doesn't respond.

Sometimes all it takes is a restart for the iPhone to become responsive again. To restart your iPhone when it is unresponsive, press and hold the sleep/wake and home buttons until the Apple logo appears (~10 seconds).

It is possible for an iPhone to become unresponsive if the battery drops to an extremely low level. Plug the iPhone into your computer or wall charger and allow it to charge for at least 20 minutes before using it again.

Plugging in your iPhone 4 does not bring it life.

Check the USB cable for damage and dirt, especially at the ends. Then try using the wall charger, as this will provide greater power input than the computer/USB.

Try using different chargers to see if you may have a problem with your charger or cord.

Inspect the 30-pin dock connector at the bottom of the iPhone for dirt, lint, and damaged pins. Clean out the dock connector very carefully with a tooth pick or soft toothbrush. If the dock connector is broken, you will have to replace it. Make sure you have the correct part, depending on if you have a GSM (AT&T) or CDMA (Verizon) iPhone 4.

You cannot get your beloved iPhone 4 to turn on.

Plug your iPhone into your computer or wall adapter to charge. If it does not charge when connected to either of these, you probably have a dead battery. The battery will need to be replaced (GSM (AT&T) or CDMA (Verizon)).

It is possible that it appears nothing is happening because the display is bad. If the iPhone sounds like it is working properly but nothing is visible, it is possible the display is bad and must be replaced (GSM (AT&T) or CDMA (Verizon)). If plugging your iPhone into a power source causes it to endlessly vibrate or sound the "connected to power" chime over and over while the display remains blank, you have a display problem that may require further troubleshooting.

If nothing else works, your logic board is probably bad and needs to be replaced (GSM (AT&T) or CDMA (Verizon)).

An error message appears as if you have connected an unsupported accessory to your iPhone

Check the 30-pin dock connector at the bottom of the iPhone for dirt, lint, and damaged pins. Clean out the dock connector very carefully with a tooth pick or soft toothbrush. High concentration isopropyl alcohol (at least 90%) and a cotton swab should be used to clean any debris that does not come off with a tooth pick or soft toothbrush. If the dock connector is broken, you will have to replace it (GSM (AT&T) or CDMA (Verizon)).

After an iPhone has been submerged in a liquid, there may be some corrosion or debris on the logic board connections that cause this error message. Remove the logic board (GSM (AT&T) or CDMA (Verizon)) and clean all of the contacts with a soft cotton swab and high concentration isopropyl alcohol (at least 90%).

You have trouble connecting to a wireless network or your calls are suddenly dropped.

The iPhone 4 has a well-documented issue regarding its antenna case design that could cause someone to drop a call if they hold the iPhone in a certain way. This problem lies in the design of the phone's hardware, and can not be fixed with any software updates or new parts. There are two solutions to this problem; you may:

• follow Apple's advice, and not hold the phone in such a way that alters the reception, or

• put a cover on your iPhone.

If your iPhone has been disassembled before, it's possible that finger oils were left on the grounding locations for the Wi-Fi or Bluetooth antennas. These oils will cause grounding issues for the antennas, which could lead to a weak signal or no connectivity at all. Be sure to clean all grounding points with an electronics cleaning solution before reassembling your iPhone to prevent grounding issues.

Your iPhone 4 turns on and appears to work, but when you plug in headphones or speakers, the audio doesn't play properly.

It's unlikely your headphones or speakers are bad, but it's worthwhile to eliminate these as the source of your problem at the beginning. Try your iPhone with another set of headphones or speakers just to make sure that the problem is with the iPhone.

The most likely cause of audio output problems on iPhone 4 is a bad audio-out jack. If you have determined that the problem does not lie in your external speakers, you should replace the headphone jack (GSM (AT&T) or CDMA (Verizon)).

Your iPhone is behaving erratically or displays the text "Use iTunes to restore" on startup

It isn't often that Apple gives specific directions about how to fix your problem! Restoring the iPhone 4 will erase everything on it, so make sure everything on the iPhone 4 is stored elsewhere prior to restoring. To restore, connect your iPhone 4 to a computer with iTunes installed. Click "Restore" on the iPhone 4 summary page (click on your iPhone icon on the left menu to find this page). Follow the directions to restore. If your iPhone 4 displays the text "Please wait. Very Low Battery," leave it plugged in. This charges the iPhone 4 enough to be able to restore. If the iPhone 4 hangs on this screen for long periods of time, you may need a new battery.

If your iPhone 4 is hanging with an Apple logo, or exhibiting some other software problem that prevents iTunes from recognizing it, you can force it into recovery/restore mode and then use iTunes to restore the software.

If the device is powered off, plug one end of your USB cable into the iPhone 4 and leave the other end disconnected. Press down on the Home button, and keep holding it down while you plug the USB cable into your computer. After 5-10 seconds, you should see a "Please Connect to iTunes" image on the iPhone 4, and iTunes should prompt you to restore the software; follow the prompts and the instructions given above.

If the device is powered on, hold down both the power and home buttons until the device reboots and displays the "Connect to iTunes" image (generally, 5-15 seconds).