Issue with Proximity Sensor during calls - Continued v2

Got to try another phone at the Apple store today - week 50 (newest I've found). It passed test 3 as well so the record for week 40 or later phones is still perfect for me while week 37 or older have all failed that test.

dbk9999 wrote:




Some reported week 42 or later is better. We've had that kind of report at least twice before which turned out to be bogus. All I can say is that I found one from week 46 that would not fail my test. It's just that one test isn't enough. We need at least a dozen or so from that period making reports. If you get almost all positive reports, that could represent a hardware adjustment.

I'm hoping the Apple stores will keep putting newer ones on display so I can check them. Until that week 46 phone, every one I ever tested failed the test. But the next newest was around week 35 or something (mine is 37).

I have an Apple store replaced iphone 4 - week 46 - which the store gave me after issues with 3G data connectivity (I started a long thread on this in this forum). Luckily it came with 4.1 (this phone was manufactured just before the release of 4.2.1) and until my 3G data connectivity issue was fixed by my carrier - Rogers - I kept it on 4.1. This was for some 6 weeks and not one problem.

When reports came in that the data connectivity issue was fixed in my area I upgraded to 4.2.1 and seemingly all was great. However, perhaps a week or so after upgrading I started noticing proximity sensor issues. Not every call and I have run your tests 3 and 6 and it passes. My first iphone 4 in about 2 months may have had 2 occurrences of proximity sensor issues.

I am trying to work out what I am doing, or perhaps have changed, in the way I talk on the phone because when I consciously sit down without moving around and do a few test calls I cannot really duplicate it.

Well, every phone I've tested, regardless of week, passes test #6 - I don't even check for that one anymore.

But I am very interested in the fact that you have problems yet you pass test #3, so let's focus on that for a moment.

First question is how you do test #3 because when I've tried to describe it to Apple geniuses and they tried the test, they ALWAYS moved it too fast away from the phone. I don't know what the speed limit is, but I think if people move it too fast, by the time the screen lights up, they have actually moved it far enough to get it to reset.

Since you've seen the video, I want to emphasize that to be SURE the test will give accurate results, you must move VERY slowly away from the phone. Moving towards the phone is quick (though I don't know the limits of that either so I just move it very quick).

Now, let's assume you did move it away slowly enough and it passes.

My next question would be what your proximity sensor problems are.

Are you disconnecting? Activating speaker or mute? Exactly what things have you experienced?

Also, do you actually see the screen come on or is something happening and you assume it must have come on? I know that for me to really see the screen come on, I have to have the brightness turned up.

But here is the thing: With one of my phones I had LOTS of disconnections which I at first thought must be the sensor issue. But turning the brightness up, looking in a mirror, and even making a video showed the screen was staying off the whole time.

My next guess was that perhaps the software was activating the icons (sensor issue), but not necessarily turning on the screen.

Over time, I found that it kept happening with the same person, but not other people. Still didn't make sense because it occurred while talking to him on his cell or his home phone and he said they were different companies, but it sure seemed as if it was just a matter of connection issues, whether ATT or his (Verizon and T-mobile).

That phone had other problems so I returned it anyway, but if you are simply getting disconnects and nothing else and you haven't actually seen your screen turn on, it might just be bad luck.

I mean, with this one person, I had it disconnect about 6 times in 15 minutes! And had other bad times with him on other calls. But in the past few months, I've never had a problem so these things can happen in streaks.

Let us know if any of this helps narrow it down.

Thanks for the reply.

I have redone the tests (3 and 6 specifically) doing it really slowly, then faster etc. Every single permutation. I cannot duplicate it. Today I have had no issues but I have been very conscious about the way I am holding it. I would say the incidence I have had in the previous two days is about 1 in 5 calls which is a fair amount when one makes about 30 calls a day. For the most part, it is activating the speaker phone although I have had a couple of disconnects to landlines which I have phoned all the time and know the connections to be good.

I have seen the screen come on (from the corner of my eye). I even installed the Call Guard app yesterday which app now registers whenever your face touches the screen when the screen is active. No hits on that yet. So very mystifying. Of course I have been through the gamut of resetting all settings, restoring, restoring as a new phone. So I am puzzled. This is something I am just going to have to keep monitoring and I will keep the thread updated.

Okay, if you are activating the speaker phone, then I would assume the screen is coming on and the sensor has a problem. Even with prior success with a land line, I wouldn't assume, based on my experience, that it is because of the sensor, but I have no other explanation for the speaker phone.

I was going to suggest Call Guard, but since you have it, at least you can avoid the screen messing up a call - and as soon as you are done, check the screen for any touches.

For the life of me, I can't figure out how you can pass test #3 and have this problem so let me ask another question - how low can you get the card before the screen turns off?

On older phones, I know of a small number who pass my test. Most of those won't go lower than 2 inches (which is also about where they first turn off). But at least one person said theirs first turned off at 3 inches and they could work it down to 1 inch.

Compare that to ones I've tested which usually start around 2 inches and I can get down to 1/8 - 1/4 inch. The difference is about the same, but that person's simply started higher. And 1 inch may be sufficient for the vast majority of people to never experience a real problem.

I'm curious as to your initial distance and how much, if any, you can get it to change. If you start lower than most - say 1 inch - and you just lose a little, it just might be enough to occasionally mess you up.

I am also very conscious of how I use the phone. Most common, if I think I may have moved it a little to create a possible problem, I just pull it 4-5 inches away for a few seconds to reset the distance. That might be useful for you.

I have an update on my week 26 iPhone4 that has been driving me crazy.

I got it soon after launch as a replacement to my very first iPhone 4 that had a crackly earpiece.

Anyway, at 4.0.1 I had no issues with the proximity sensor. However, I could not use any of my Bluetooth headsets because everyone said I sounded like I was under water. Then I upgraded to 4.1 because of the BT fixes and it all went to crap! Complete crap. Literally can not make a phone call without the screen flashing on and off and on and off. But hey, at least BT worked!

Now, I had been waiting to upgrade to 4.2.1 because of the untethered JB, so I finally did so this past week, and FINALLY I can use my phone by holding it to my ear. There's no question Apple made some further adjustments to the proximity sensor in 4.2.1. To test this, I reverted back to 4.1 just to make a few test calls. At 4.1 again, fresh installed, the screen flashed on and off and on and off while on my very first call. Then I put back 4.2.1 and have had no issues..

No issues? Well.. ok that might be an overstatement. I have found that if I dial a number and very quickly put the phone to my ear, the screen stays on and visible for maybe 3 or 4 seconds or so, before it turns off. This only happens occasionally. If I wait a second for the call to start ringing before I put the phone to my ear, it's fine. It's not 100% fixed, but I'll take 95% fixed at this point!

My wife's week 32 iPhone 4 has EXACTLY the same issues as me at iOS 4.1, but I haven't upgraded her to 4.2.1 quite yet.

It's clear to me Apple botched the proximity sensor on these phones. I have friends who had problems out of the box at 4.0/4.0.1 with the proximity sensor, whereas my iPhone 4 did not. Then they upgraded to 4.1 and the issue was resolved for them, whereas my iPhone 4 and my wife's iPhone 4 became unusable without a headset at 4.1.

I have no idea what happened during manufacturing, and it would be fascinating to have an engineer rip two or more of these phones apart to see exactly what caused this.

In any case, 4.2.1 finally fixed the proximity sensor for me.

Very interesting - especially since when you reverted to 4.1 the same problem returned.

Sometimes it seems just the process of upgrading screws something up - no idea why. Just like some problems go away by resetting or something. But since yours could repeat the problem, it probably was more meaningful than that.

This repeatability also gives another example that something in 4.2.1 changed the sensor operation, just as I found when I could no longer find phones to fail test #6 if they had that upgrade.

I tried the test of putting the phone to my ear quickly, but don't have the same results. It might be slightly slower at turning off than if I delay putting it to my ear (I might test more later), but not several seconds.

You might want to check the serial numbers on both your phones. If the first two numbers are the same (factory number) and the 4th and 5th numbers are the same (week made) or maybe consecutive weeks, it may reveal that your phones were victims of a temporary quality control issue.

I just haven't heard two phones with the same issue you describe before.

One other thing. I'm pretty sure that Apple also has done something hardware related since, so far, I can't find any phones that fail my test starting with week 40 (I have not tested any from weeks 38-39) while all I tested up to week 37 would fail my tests.

I'd love to know what it is too. It might not even be a change in hardware components. It could be they discovered a problem in how the sensor was mounted or something and simply made a tiny adjustment.

Like you, I'd love to know what it is.

Just a brief update. It has not happened today either but I did redo all the #3 tests. I will start at 3" or so and slowly move down. The very lowest I can get the card down before the screen darkens is 1.5". Generally the screen will darken at 2". This is after 30 or so attempts. Continuing down slowly or rapidly to 0 distance changes nothing. If, after the screen darkens I slowly raise the card the screen will light up at 2.25"-2.5" or so (doing this slowly). Going all the way down to zero distance after the screen darkens and then going up again changes nothing. I do not know why the problem has not reoccured, Prior to my last experience of improper behaviour I had already done one clean restore and reset all settings at least twice. Since the last time I have had a problem I have done perhaps one "reset all settings".

Interesting. I've had some exceptions to the norm on my tests. Usually it will initially darken around 2 to 2.25 inches, but I've had it happen over 2.5 and maybe close to 3, but that isn't normal.

That yours doesn't change as the test progresses definitely leaves us with a mystery as to why the sensor was giving you trouble.

Could be there is a pattern of usage I haven't even considered, let alone tested for, and you just happened to do it for awhile.

Or the sensor is a bit flaky - working most of the time, but occasionally crapping out.

To reply to your post, here are the serial numbers:

Mine: 82062Rxxxxx
Wife's: 840320xxxxx

And I should clarify. The problem my wife's phone has is just the proximity sensor in general at 4.1, not the "not turning off for a few seconds" issue I described my phone doing occasionally at 4.2.1. So no, we both don't have the not-turning-the-screen-off issue I described.

Message was edited by: WGrose

The only problem I seem to be experiencing lately with my iPhone 4 now on 4.2.1 is a screeching/whining sound which starts as soon as it starts ringing in my ear before the call connects. I then have to hang up and call back, and it doesn't repeat.

Happens randomly, and I'm not sure why...

Something doesn't make sense with those numbers, unless Apple suddenly changed their whole system.

The weird thing is with digits 4 & 5 which are supposed to be the week of manufacture (the 3rd digit is the year, thus almost all would be 0 and the very newest ones would be "1").

But yours shows 62! I think you previously said it was week 26 - did you make a typo?

Screeching and whining? Dang, you have an odd phone! Never heard that one before.

Sorry that should indeed have been 26, not 62!

Mine is from week 39 and it definitely has the proximity sensor problem: I'm using a pad of Post-it notes, place it on the upper half of the phone, slowly lift it up until the screen lights (dimly) and then quickly drop the pad on the upper half of the phone again. Repeating this procedure a number of times (typically 5 - 10 times) randomly results in a screen that is still active (dimly lighted with the touchscreen active) although the pad of Post-it notes is laying flatly on the upper half of the phone.

iPhone 4, iOS 4.2.1 (upgraded from 4.1), serial number 7U039...

In daily life, it is better with 4.2.1 than it was with 4.1, but it still happens regularly that I accidentally mute an ongoing call. It seems that I was "lucky" enough to get one of the last bad ones ;-(