iPhone 4 Troubleshooting Guide

General Guidance:

Problems and Fixes:

The 4 Rs

This list of escalating fixes that can solve a surprisingly large number of iPhone 4 problems.

1. Reboot (hard reset). This may yield success for slow 3G data transfer and other issues. Hold down the sleep/wake and home buttons simultaneously for roughly 15-20 seconds, until the screen powers off then an Apple logo appears, which signifies a reboot. Some problems may require (oddly) that this procedure is performed twice.

2. Reset all settings. This may resolve proximity sensor issues, slow throughput, FaceTime problems, loss of cellular service and more.  It appears that the reset may restore disengaged hardware components and  clear corrupt data that prevents proper connectivity. Navigate to Settings > General > Reset > Reset All Settings. Note that this will erase stored messages, passwords and other information.

3. Restore, but not from backup. This procedure can resolve app crashes, unexpected resets during phone calls, battery drain and more. It appears that bad holdover data from iPhone backups (especially those created for previous iPhone models)  can cause various issues. Restoring as a new phone will delete contacts and other data, but may resolve the problem. To do so, connect your iPhone or iPod touch to your computer, click “Restore” in iTunes, then choose “setup as new phone.”

Use these tips from Apple to preserve data during the procedure.

some problems may require that the phone is restored while it is in DFU (device firmware upgrade) mode. Doing so may resolve issues with Exchange, an inability to send and receive MMS messages, device slowness and other problems.

To perform a DFU restore, follow these steps:

1. Backup your phone and preserve data. Follow the steps in this Apple Knowledge Base article to transfer your purchases and backup your iPhone.

2. Put iPhone into DFU mode. Connect your iPhone to your computer and open iTunes (if it doesn’t open automatically). Hold down both the top (sleep/wake) and home buttons for exactly 10 seconds, then release the top (sleep/wake) button but keep holding the home button until  iTunes displays a message stating that a phone in recovery mode has been discovered.

3. Restore. Press the restore button and allow the phone to complete the restoration data. After it is done, select setup as a new phone.

4. Restore your backup (optional). Next, you can restore the phone again in the normal fashion (not DFU mode) using the most recent backup rather than setting up as a new phone. However, this may cause the original problem to return in some cases. If the problem returns, follow steps 1-3 again and do not restore your backup.

4. Reseat your SIM card. This fix is effective for some data throughput, signal or cellular service issues. Simply remove your SIM card, clean it lightly using a dry cloth, ensure that there is no debris in the SIM slot, then reinsert the card, ensuring a snug fit. Instructions for doing so can be found in this Apple Knowledge Base article.

Determining Upgrade Eligibility

Wondering if you’re eligible for an AT&T subsidized upgrade to the iPhone 4? You can find out in 10 seconds or less by dialing the following on your keypad, then pressing “Call”:


You’ll receive a text message back that states your eligibility, e.g.:

“As a valued customer, we can offer you an upgrade with a new 2-yr commitment and waive the $18 upgrade fee.”

Feedback? info@appletoolbox.com.

Signal Drops or Degrades When Held a Certain Way (“Death Grip”)

Several iPhone 4 purchasers have noted an issue in which the device loses signal reception and network speed when it is held in a certain manner–specifically when the phone is gripped on the sides near the bottom of the device, where the small seams (black bars) are. Here are two YouTube videos demonstrating the phenomenon:

So, it appears that closing the circuit generated by the antenna (which runs along the metal strip surrounding the iPhone 4) with your hand can cause a significant degradation in signal.

Because of the location of the antenna, some users have noted that this problem is more likely to occur when held in the left hand.

Apple issued a letter addressing the issue. Although the letter does not explicitly mention that the forthcoming software update will result in any reduction to dropped calls/connections, circumstantial evidence suggests that the update may in fact deliver such improvements for the following reasons:

3G versus EDGE. The iPhone 4 automatically switches to EDGE from 3G when the 3G signal falls below a certain threshold. One hypothesis holds that the new signal recognition algorithm included in the iPhone 4 software update will more accurately recognize when a 3G signal is untenable, and more aggressively switch to EDGE before calls are engaged. Because calls drop when the switch from 3G to EDGE is made and EDGE coverage is significantly more vast than that of 3G, this change may result in a real-world reduction in dropped calls.

As noted in our list of fixes for the reception issue, several users have experienced faster throughput via EDGE than 3G when this issue manifests.

Bad calibration. Some RF antenna engineers suggest that faulty calibration of the iPhone’s signal recognition mechanism may result in unnecessarily dropped calls. In other words, the iPhone 4 may be incorrectly triggering call drops when a viable signal exists. The recalibration included with the forthcoming iOS software update may improve this situation.

A software signal boost. Previous iPhone software updates have reportedly boosted signal strength by increasing power to the antenna.  The forthcoming iOS software update may include a similar change, which would likely result in a slight degradation of battery life, but improved cell reception and signal strength. Because the loss-of-reception issue is much more likely to occur in areas where signal is already weak, such a change could result in more reliable overall connectivity.

In the meantime, here are some potential solutions:


Use a case. As demonstrated in the second video above, simply putting a case that covers the seams on the iPhone 4 can alleviate this issue, as it blocks your hand from closing the antenna’s circuit. Several users have experienced success with Apple’s “bumper” case.

Hold the phone differently. Simply holding the device in a manner that does not cover the seams at the bottom can eliminate the issue.

Scotch tape. A surprisingly effective and tremendously easy fix: simply adhere a small strip of scotch tape over the seams on the iPhone 4. This prevents the hand from closing the antenna circuit (as described above) and resolves the issue for a number of users.

Turn off 3G. Some users have reported that the signal degradation issue does not occur if the iPhone 4 is operating in EDGE-only mode. To turn off 3G, navigate to Settings > General > Network and slide 3G to off.

Accidentally Hangs Up or Mutes During Calls When Held to Ear (Proximity Sensor Issue)

A number of users have experienced an issue in which the iPhone 4 unexpectedly mutes a call, hangs up or engages FaceTime when the device is held up to the ear. This problem occurs due to apparent under-sensitivity of the iPhone 4’s proximity sensor, which turns off the screen (and touch capabilities) when the phone is held to the ear. In other words, the proximity sensor does not properly engage, and the user’s cheek or ear accidentally touches the mute button or other functions.

In other cases, it appears that the proximity sensor is not engaging at all, leaving the screen on and touchable while the iPhone 4 is held to the ear.

Potential fixes

Reset all settings. Although this will not help with an under-sensitive proximity sensor, it may help when the proximity sensor does not engage at all. It appears that the reset may restore a disengaged sensor. Navigate to Settings > General > Reset > Reset All Settings. Note that this will erase stored messages, passwords and other information.

Restore, but not from backup. It appears that bad holdover data from iPhone backups can cause this problem in some cases. Restoring as a new phone will delete contacts and other data, but may resolve this issue. To do so, connect your iPhone or iPod touch to your computer, click “Restore” in iTunes, then choose “setup as new phone.”

Remove case. Some users have reported that removing cases (especially those that were designed for previous iPhones but fit on the new iPhone 4) can mitigate this issue.

Launch another app. Albeit kludgy, you can open another app after you’ve made a phone call to obviate this issue. Right after making or receiving a phone call, press the home button then launch an innocuous app (such as the calculator app) that won’t invoke any unwanted functions if accidentally tapped.

Slow Downloads and Data Over 3G Connection

Although most users have reported faster 3G data throughput from the iPhone 4 relative to the iPhone 3G and iPhone 3GS, some users report dramatically slower speeds in locations where their previous iPhones delivered normal speed. In some cases, the phone displays the message “Could not activate cellular data network” despite full signal (all bars).

Apple Discussions poster bgrind1 describes a test in which two iPhone 4 units placed side by side both delivered dismal 3G throughput, while an iPhone 3GS in the same location delivered normal speed.

“I just visited an ATT store to ask about this issue. The rep and I tested their two display iPhone4 models and both responded exactly as mine, with little or no 3G data. We simply tried to open yahoo on both display phones as well as mine. All three after 2-3 minutes responded with an error stating no response from server, or something along those lines.

“Meanwhile, the iPhone 3GS model 5 feet away, also connected to 3G, responded very quickly, to all websites, apps that require data, etc.”

Note that this issue is separate from the signal/reception loss issue (see: iPhone 4 Loses Signal [“Death Grip” Antenna Issue]: Why and How to Fix [Scotch Tape]. In this issue, signal and reception remain strong, but data throughput is extremely slow or wildly fluctuates, even though grip is not changed and the phone is in the same location.

Another Apple Discussions poster, USBSlave, writes:

“At some points it works fine but most of the time I can pull down a few KBs a second if I’m lucky preventing me from using Data on the phone. Voice and Texting work fine at all points in time. The phone shows 5 bars and I used an iPhone 3G in the same office for a year without a single issue. While I generally use my phone at the office most the problem happens everywhere so its not just one area. Basically the download speeds will spike to 1-4 MBPS for a minute or less then the rest of the time all the speed apps gauge me at about 1-100 KBPS. Upload speeds are always high its only download.”


Reset network settings. On your iPhone, open Settings, then navigate to “General” in the left-hand pane. Scroll down and tap Reset, then select “Reset Network Settings.” This will delete any stored WiFi passwords and other information, but may result in a faster connection.

Hard reset. Hold down the sleep/wake and home buttons simultaneously for roughly 15-20 seconds, until the screen powers off then an Apple logo appears, which signifies a reboot.

Reseat SIM. Remove your SIM card, clean it lightly using a dry cloth, ensure that there is no debris in the SIM slot, then reinsert the card, ensuring a snug fit. Instructions for doing so can be found in this Apple Knowledge Base article.

Switch to EDGE. Albeit a less-than-ideal solution, several users have experienced faster throughput via EDGE than 3G when this issue manifests.

“No SIM Card Installed” Error

Some iPhone 4 users have reported an issue in which the phone suddenly displays a “No SIM Card Installed” error, either while attempting to make phone calls or during routine usage.

Apple Discussions poster macoverclock writes:

“Keep getting the “no sim card installed” error. phone works for a bit then go to check my email and the error has come up. shut the phone off and turn back on and the sim card is found then a half of an hour later the same error comes up again. this has happened 5 times in the last 5 hours.”


The most reliable fix for this issue is to simply remove your SIM card, clean it lightly using a dry cloth, ensure that there is no debris in the SIM slot, then reinsert the card, ensuring a snug fit. Instructions for doing so can be found in this Apple Knowledge Base article.

Other users have reported that briefly turning on Airplane mode (in Settings) then turning it back off can resolve the problem.

FaceTime Doesn’t Work; No Option in Settings: Fix

iPhone 4 users have reported three distinct FaceTime issues:

1. No FaceTime option appears in the Settings app. In other words, you do not have the option to turn FaceTime on or off, and no functionality appears in the phone app.


First, try this process:

  1. Navigate to Settings > General >Restrictions and select “Enable Restrictions”
  2. Set the FaceTime restriction to on
  3. Select “Disable Restrictions”
  4. Go to Settings > Phone, and you should now see a FaceTime option, which you can turn on.

Failing the above, restore your iPhone 4 as a new phone. This will delete contacts and other data, but may resolve this issue. To do so, connect your iPhone or iPod touch to your computer, click “Restore” in iTunes, then choose “setup as new phone.”

2. FaceTime button missing from phone calls. In this case, the FaceTime option exists in Settings, but you cannot initiate FaceTime sessions from the phone app or from the contact screen. You may see a hold button instead of a FaceTime button.


Make sure FaceTime is on. Go to Settings > Phone and make sure that FaceTime is turned on. If you don’t see a FaceTime option, follow the procedures above.

Reset all settings. Navigate to Settings > General > Reset > Reset All Settings. This will erase stored messages, passwords and other information, but may resolve this problem.

Failing the above, restore your iPhone 4 as a new phone as described above.

3. FaceTime doesn’t work on some Wi-Fi networks due to firewall restrictions.


We noted a fix for this issue here, which Apple subsequently noted in a knowledge base document.


  1. Cheap SSL says

    I�m looking at an iPhone 4 upgrade here pretty soon. My Blackberry died about two weeks ago and I�ve been stuck with a Rockr. It happened just long enough after the preorders that I have to wait to get one now. Doh!

  2. says

    Disabling 3g worked for me. I wasn’t even able to accept or receive calls from certain phones until I disabled it. It was very spotty. Is everyone really accepting the flaws in this phone because it’s Apple. I’ve never owned a phone where you would have to make so many concessions in order for it to work correctly. Hopefully they can get a fix in soon. It would be a shame to have to send it back. Other than the phone connection problems, it really is a nice device.

  3. says

    in iphone 3gs version 4 after every 3 minutes iphone symbole appear and showen 10 second .after 10 secnod iphone main screen showen. pls forwerd me this problem solution

  4. says

    You realize of course that this list is an abomination.

    Hokey reboot advice, USE a case. DONT use a case.

    Turn off 3G. The proximity sensor is only sensitive to 1/4 inch where prev iphone it was sensitive to 1/2 inch.

    None of these suggestions is going to really work. This is fiddle advice.

    Apple needs to fix this phone.

  5. says

    I still have over two weeks to return the phone so I am into a hard evaluation period. So far this is a $200.00 toy and not a phone. I need it to be phone first and foremost and a toy second. Why is it a bad phone? Simple, reception or lack there of. The combination of I-Phone and AT&T is a lethal combination for product satisfaction. I certainly do not need the CEO (Steve Jobs) telling me that first there is no problem then hold it like this and not like this and here have a glorified rubber band you will need to use. Needless to say this whole experience is not going well. Apple needs to do some hard and fast repairs and/or replacements or face world wide reprisal through refunds and thought the courts. At this point I may be spending my two year contract with Sprints HTC EVO 4G. Now can someone jailbreak the EVO? And Steve you need to get into bed with Flash also. Come on lets get with the program.

  6. says

    my iphone has experienced ALL of these problems. and now the screen has zoomed in and won’t zoom out, so i can’t even get to the reset option. i’ve always held apple products in the highest regards, but i hate this phone. i’d rather have my 4 year old razr and am working on an apology letter to t-mobile for switching to at&t.

  7. says

    I am having a problem with the texting app. Sometimes the send button doesn’t activate so that I can not send the text that I just typed. Nothing I can do at all. Some times it does. Other times, I send a pic via text and it goes through to the recipient but it tells me that it didn’t. I resend only to find out that the first and second attempts were successful. My phone tells me that neither were.

  8. says

    Dear Sir,
    Power adaptor was bernt when newly purchased iphone 4 was pluged to recharge. Thereafter, iphone does not power on. When it is connected to the computer the sreen just illuminate nothing displaying for few second and off. This repeat in about 10 second intervals.
    Your advice is highly appreciated to rectify the fault.

    Thank You!


    Sri Lanka.


  9. says

    i brought a new 4g phone in uk 2 weeks ago it was fine in its first week and than my camera is not working at all i have tried every thing possible from rebooting to reset factory settings. is their any one who can help me in this?

  10. says

    I have enjoyed using the first iPhone 8GB- And my favorite cell was the 3GS- it never dropped calls Anywhere- and was super fast. But the phone was damaged a few months ago- I tried to get a duplicate phone- but they were sold out everywhere- hence I needed a phone- So at the apple Store- the only phones they had were the IPhone 4. This is the worst phone I have ever owned- okay- we all can deal with dropped calls- (get used to it with any phone) but my new iPhone 4- while ringing just made a horrible noise- and the sound was gone- (i have installed soundcards in computers- and it’s obvious the sound chip is fried) No the phone was nowhere near any water/ but safely on a side table. I am missing my 3GS. I don’t mind paying for quality/ but what are my options? Don’t get me wrong- No phone can come close to the iPhone -it’s the best. That is why I am just disappointed with my new IPhone 4. : (

  11. says

    When I open a thread of texts between myself and another person then try to edit the contents, the “delete” and “forward” buttons at the bottom are greyed out, hence do not respond. Help!

  12. says

    My iphone4 is totally not working. It’s suddenly shut out by itself without me turning off in the main switch. when i tried to turn on the main switch it’s not working nor open itself..

    • ian says

      my iphone 4s has also shut down on its own and will not restart or even take a charge. Does anyone have a fix for this?

  13. Martin says

    My iPhone 4 keeps crashing,even during calls. Have done everything suggested in terms of closing down apps and re booting. Was suggested that I up grade with iOS 5. Have done that and enjoyed the benefits in between the phone crashing still. Just out of warranty . Very fustrated with it !

  14. Darrell Dable says

    My Iphone 4s has recently changed display colors. It is all black and brown display and all pictures are basically whited out. You can see the figures in the pictures, but that is it, they all appear white. What can I do to fix this issue?

  15. andrew says

    im having problems with my iphone 4. its completely blank, but when i put it on charge at the mains it says connect to itunes. but when i do so nothing happs and my computer doesnt even recognise the devise. can anyone help?

  16. Saad Salman says

    I am errasing all data and content but it’s not working properly so please guide me how i can delete all Data and Contents… whenever i try to do this it doesn’t show apple logo just show a processing sign…

  17. Jan says

    Sound has gone from my iphone4 it does ring but that’s all now I’m having network error have gone into settings and all is ok!?????

  18. Casmiro Martin says

    With my Iphone 4S I am facing a problem and I dont know how to get rid of it. Can you just assist me. Everytime the ringer is getting on even if I try to put it low it increases on its own. Even without the protective cover it is same

  19. Anne says

    My iphone 4 has problem.,even if there is a signal i am unable to receive a call when it try to call its ringing bu no more incoming call reflected and even txt messaging,.,and when i’ll make a call it hangs,.,what can i do,my iphone has been jailbraked,.,please help me to resolve this problem,.,

  20. Buddy says

    Hi, for no apparent reason my iPhone 4S out of the blue won’t accept my 4 digit password. I haven’t changed the password and each time I repeat it, it locks me out and will only allow emergency calls.
    Not sure what to do. Have tried turning off etc but to no avail.
    Any suggestions guys?

  21. himanshu patel says

    i have iphone 4s & ireceived a message for software update. so i proceedfor that.
    my iphone 4sgot hanged it shows only one message”connect to itunes.” when i connect to itunes the site does not give me permission to enter it.give me a way.

  22. mberg says

    im experiencing a serious issue with my iphone 4 it has a message that has been popping up every 3 seconds for the last day ive tried rebooting and resetting settings. the message is asking me to fill in my apple ID to sign into either facetime, icloud, or imessage. ive tried rebooting and resetting my settings but even if i put in the code it wont stop popping up. has anyone else experieced this problem if so, HELP!!!

  23. lorraine appoo says

    i have a iphone 4s when i plug it into charge the apple symbol just repeatedly comes on and off and thats all it does…..can anyone help fix this plz??

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