The iPhone 4's second Vietnam: the proximity sensor (updated 3x)

The iPhone 4's second Vietnam: the proximity sensor (updated 3x)

Summary: A lot of attention is being paid to the apparently flawed antennae design on the new iPhone 4, but what about its buggy proximity sensor?

TOPICS: iPhone, Mobility

The iPhone 4's second major problem isn't getting nearly as much attention as the first, but it's arguably just as bad -- because it causes you to drop calls. The only difference is that your face is to blame, not AT&T's craptastic network.

The proximity sensor in the iPhone 4 is what tells it how close the phone is to your face so that it can turn the touchscreen off while you're making a phone call. This has the effect of a) saving battery power, and b) preventing inadvertent touches of the screen by your face.

The problem is that the proximity sensor in the iPhone 4 is on a hair trigger. It's either not sensitive enough, miscalibrated or both. In over three years of using the iPhone 2G, 3G and 3GS I've never accidentally hung up on, muted or put a call on speakerphone while holding it up to my face -- not once. Yet I've done it a half dozen times on my iPhone 4 over the past weekend.

As I first blogged about in my iLemon post, I frequently put calls on speaker, or accidentally "FaceTime them" or completely hang up on calls altogether because the proximity sensor errantly wakes the screen, which some part of my cheek proceeds to touch.

And I'm not the only one. There are 66 pages of proximity sensor complaints in this one thread alone (which already has over 100,000 views) from iPhone 4 users in Apple's own support forums.

What bothers me is that the prox bug -- which seems to be more related to software than hardware -- seems like childsplay compared to the antennae/reception issue. Also, it only affects the i4 and so a fix wouldn't have to be QA'd for Apple's other iPhone handsets.

Can't Apple just dial back the sensitivity on the proximity sensor a couple of notches and release a software update? Why is Apple waiting for a "few weeks" and rolling everything into one massive update when it could probably release a proximity fixes for afflicted iPhone 4 users right now? It seems like a comparatively trivial bug and Apple is making its iPhone 4 customers suffer needlessly in the mean time.

Does your iPhone 4 proximity sensor act up?

Image: 9to5Mac

Update: Anthony Kinson has posted a video of the bug in action. Pay attention to the erratic behavior of the proximity sensor beginning at around the 1:34 mark.

Update 2: Another video demonstration is here.

Update 3: A PowerPage commenter reports that Apple is deleting prox bug threads on its

Update 4: Macworld has reported that some users are having success with resetting some of their iPhone's settings.

Many affected users report that either a Settings reset or a hard reboot fixes their problem. One Apple support thread recommends that users open the Settings app, then go to General -> Reset, and choose "All Settings" at the top (note: this will not erase your apps, media, or other data -- that's what the "Erase All Content and Settings" button just below this option is for. "Reset All Settings" just reverts any Settings preferences you've customized back to their factory defaults). One Twitter follower, Brian Partridge, reported that AppleCare told him to just use Reset -> Reset Network Settings, not all settings, and it worked.

Topics: iPhone, Mobility

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  • Same on my updated 3GS

    The same happens with my iOS updated 3GS. Previously I have never had a problem with this sensor, since the update I triggered the speaker during many of my calls. I doubt this would be a coincidence... I hope Apple will solve this through a software update soon.
    • RE: The iPhone 4's second Vietnam: the proximity sensor (updated)

      A BIG YES to that!!
      I am so frustrated on my 3GS.
      Updated to iOS4 and now more than a third of my calls when I take the phone from anywhere nere my face the screen is black and stays that way.
      Usually I have to do the Home/Power button hold to get the screen to come back on.

      Apple store answer: "Sir, we are aware of this and there will be a fix soon. Until then I recommend using a BT earpiece. We have several good models in stock..."

    • Ditto with my 3G

      @WillCroPoint<br><br>I had two weird hangups that seemed to be related to the proximity sensor. Never happened before I updated to iOS4.
  • You just had to say..

    You just had to say AT&T "craptastic network", didn't you? Even though in the open paragraph you mention the faulty antenna.
    • RE: The iPhone 4's second Vietnam: the proximity sensor (updated)


      We'll assume from your comment that AT&T is great where you live and work.

      AT&T's network is craptastic where I live, work and most places I go. When paired with Apple's craptastic antennae you have a disaster.

      Obviously YMMV.
      - Jason
      Jason D. O'Grady
      • Just A Simple Question...

        @Jason D. O'Grady <br>with the launch of the iPad, it seems that apple would have had complete freedom, to move the mobile connectivity to any of the cellular providers ???<br>And yet apple continued to partner with AT&T...<br>Have you any insight into this irony ?<br>If AT&T is so bad, it seems that apple could improve their own reputation by partnering with someone else ??
      • RE: The iPhone 4's second Vietnam: the proximity sensor (updated)

        @Jason D. O'Grady

        cut the crap and not compare this issue to the Vietnam War alright..people are not losing their lives due to a poor cell net, bad antenna or proximity detector
      • RE: The iPhone 4's second Vietnam: the proximity sensor (updated)

        @Jason D. O'Grady I like the term Craptastic. It is the correct use of the word. My AT&T is good / great in the DC area, that said, it doesn't work well in Durham / Chapel Hill. By "doesn't work well" I am in fact saying it's Craptastic. Enjoyed the blog, especially having other sources show the issue.
  • RE: The iPhone 4's second Vietnam: the proximity sensor (updated)

    Sorry but the author isn't the brightest bulb on the tree. The iphone 4 antenna problem isn't because of the carrier.
    • RE: The iPhone 4's second Vietnam: the proximity sensor (updated)

      Was that necessary? I *know* that the antennae problem isn't directly related to the carrier, but when both are bad, it's a recipe for disaster. And that disaster is the iPhone 4.
      Jason D. O'Grady
      • RE: The iPhone 4's second Vietnam: the proximity sensor (updated)

        @Jason D. O'Grady

        Exactly how many iPhone hardware problems have to be discovered before you finally admit that the problem isn't the carrier?

        This is ridiculous, I get so sick of this, Apple people first refuse that there is any kind of problem with an Apple product, and then when the problem is pointed out in such a way that it cannot possibly be denied, promptly points the finger at someone OTHER than Apple?

        There are 87 million AT&T customers, and yet the only ones who seem to complain about coverage are the 6 million who use the iPhone....coincidence?

        Is it really so hard to believe that the same company which produced complete duds like the Apple III and the Lisa could have made a bad phone?
        Doctor Demento
  • Apple controls both hardware and software so...

    ...Apple gets the blame for everything. Apple has got to realize that having control of both S/W and H/W takes alot more responsibility, especially, as Apple has, a very small product line, in this case only one phone. Apple cannot afford to let their game down.<br><br>Microsoft for example, can walk away and doesn't have to with issues. Microsoft is invisible to most consumers as Dell, HP, Sony etc sell the computers to people. Microsoft knows how hard it is to control both H/W and S/W by the amount of trouble they had with their Xbox, fortunately for them, that was only a game machine.<br><br>Apple has got to hire more people for testing and quality.
    • Indeedio!

      @root12 Apple apologists tell us how wonderful it is having one company control the entire HW/SW experience. Now they can choke on it.
  • Jason - have you become a disgruntled Apple customer?

    You're starting to sound like a guy who put all his eggs in a nice shiney basket, only to find that it's turned into a wet paper bag.

    Don't tell me you also put your life savings into a Madoff fund.


    Seriously... Can we now please stop peddling the myth that Apple customers are always 100% satisfied. 9 out of 30 iPhone 4's returned is not a good example of satisfied customers.
    • Let's wait for real numbers before we draw our conclusions

      @iTeaBoy: First, 9 out of 30 is anecdotal evidence. Second, even if it were accurate, it's too small and unrepresentative a sample size. I'm not saying these numbers may or may not prove out. I'm saying that there is no reliable evidence yet of the number of phones returned. Let's wait until the number or percentage of returned phones has been verified before we start using unsubstantiated numbers in our analyses.
    • RE: The iPhone 4's second Vietnam: the proximity sensor (updated)

      I don't know about disgruntled. Disappointed is more like it. I just want my damned phone to work. All weekend I had to apologize to people for hanging up on them, putting them on hold and randomly dialing in their ear. Luckily it was the weekend and most weren't "business" calls. Unfortunately, the holiday weekend is over and now I've got business calls to make. How long should I have to apologize for my phone? A "few weeks?" Apple needs to fix the prox bug now or my iPhone is going into a drawer. My Evo and DroidX don't do this.
      Jason D. O'Grady
      • RE: The iPhone 4's second Vietnam: the proximity sensor (updated)

        @Jason D. O'Grady why don't you use bluetooth?
        Ron Burgundy
  • RE: The iPhone 4's second Vietnam: the proximity sensor (updated)

    Thanks for highlighting this. I have suffered since day-one and added to the burgeoning list of complaints on Apple's forum.

    Having said that, there is a glaring error in your piece, and that is the suggestion that the sensor needs to be attenuated. Of course the problem is actually the converse, in that it is not sensitive enough and needs to actuate when further from one's face than is the case at present. iP4's predecessors had a prox sensor which kicked-in at a far healthier 2 inches or so, rather than the half an inch of the present model.


  • RE: The iPhone 4's second Vietnam: the proximity sensor (updated)

    I haven't had a single problem with my iPhone 4.
    Never dropped a call, never had a problem with the proximity sensor or anything. I'm actually more happy with this phone than any I have owned.
    Just my experience.
  • RE: The iPhone 4's second Vietnam: the proximity sensor (updated)

    Why does it even need a proximity sensor? Sounds like an overly complicated solution to a simple problem. Why not just lock the screen when in a call, and to wake it, you must touch and THEN 'slide to unlock'. Inadvertant taps may wake the screen, but it won't unlock it unless iPhone users are rubbing their phones all over their faces.