Issue with Proximity Sensor during calls - Continued v2

Turned auto brightness off on my phone and reset network settings at the same time. Not sure which one fixed it, but proximity is now working.

dbk9999 is by far the expert on thism but I want to say that like most things what seemingly fixes a problem generally is just a temporary fix, especially the resetting network settings, resetting all settings etc. Keep us updated.

Like ticksg said, we've seen people report success with network resetting and a host of other things, but we also have had them come back later and say it wasn't working right again.

One thing it is important for people to report is exactly what their symptoms are. If it is just about having calls cut off, that may NOT be the sensor. I know because I've had streaks where I would get cut off every 2-3 minutes on some calls, yet I was watching the screen (turned up to fully bright so it was easy to see if it lit up) and even had the iSight camera recording me. The phone never lit up!

So, it wasn't the proximity sensor in that case. It was a problem with either ATT or the other person's phone company.

The thing is, I could have a bad streak of these cut-offs and then suddenly no problem at all. It would have been easy, if I hadn't watched carefully, to think the sensor suddenly started working when, in fact, it had nothing to do with the sensor.

Now, if you activate mute, speakerphone, etc, then it is probably the sensor.

I finally decided to stop playing around with my phone and took it in to the local Apple store. According to the Genius there is a database of iphone 4s whose range of serial numbers and production dates are prone to erratic proximity sensor operation. Apparently my week 46 fell within that range.

He swapped mine out for a week 8, 2011 model (which is no doubt the date of refurbishment) and so far all is good (although I seem to be having a higher incidence of dropped calls).

Interesting, since all phones I've tested from week 40 on passed my test. Of course, that's still a limited number. Quite possible that the failure rate is much better on them, but still not as good as they should be.

Dropped calls can be weird. Almost every dropped call I've had (not a sensor problem) has been when talking to the same guy. The biggest mystery is that it occurs on both his home phone and cell phone - two different companies.

I went to my Apple Store over the weekend to have them look at my proximity sensor not working and the "genius" verified the problem and promptly replaced my unit. However, he did not check it and I later found that it still does not work.
Not only that but I found that after syncing, I did not recover all the information and much was lost to my bitter disapointment. I guess I am going to have to go back again but next time I was have the so-called "Genius" show me that it actually works.

My new/refurbished iphone 4, 8th week of 2011 is doing the same thing again. Not every call, perhaps 1 in 4 and as usual it is putting people on the speakerphone. I have done your test #3 4 times and I cannot get it it down below say 1"-1.5" or so without the sensor activating. But, as I said, this phone, like the previous one, does it sporadically. I don't know what comes next. Perhaps I should just use Call Guard. Unfortunately, that app is a bit of a cludge and not as useful as an app that is available if you jailbreak the phone.

Well, this is interesting - in a bad way! Was definitely hoping that newer models had virtually eliminated the problem (based on my tests). Of course, of millions of phones, some will have issues. Can always hope that is the case with yours. If it happens on another exchange, that would be a heck of a coincidence though and I'd assume things are still a more serious problem.

Two things I have questions about. Just so I'm sure what you mean about doing my test:

The screen ALWAYS stayed off once you got down to 1 or 1.5 inches? That's a sizable difference. While I would think 1" would be, usually, okay, it may be possible, with the right placement and shape of the ear, that it could be insufficient. Not sure, but just maybe. I would think 1.5 inches would be virtually impossible to reach as long as it is on the ear.

Since it is your speaker phone coming on, I'm pretty confident it is the sensor though (dropped calls may not be).

If you don't mind spending the money, using Call Guard might at least give you some useful info - like how often you touch the screen when it comes on AND where you touch it.

My other question - and you may not know the answer - is what does the week number mean if it is refurbished?

That is, if they take a week 40 phone and refurbish it, does it keep the same week number, or do they change it to the refurbished week?

I would hope it keeps the same number because if it doesn't, figuring things out becomes far more difficult!

You've probably seen me post about this before, but I'm pretty conscious of how I'm moving the phone while talking. If I notice I've lifted it off my ear a little and put it back, I realize that could mimic test #3. Therefore, I'll deliberately move it several inches away for 2-3 seconds and then put it back on my ear. That resets things to the original distance.

One other thing, about Call Guard. True, it's a cludge, but mostly when you start the call and app. If you hang up by pressing the top button, you'll both end the call and quit Call Guard so at least that part is simple.

dbk9999,

I tried your test #3 again and I still get the same result. No less than 1" and the proximity sensor activates.

Now a couple of points. I am almost completely sure that when a telephone is returned to be refurbished, the serial number is changed to incorporate the date of refurbishment. There used to be, I recall, a clear way with which to distinguish refurbished phones and that was the first 2 characters/digits - something like 5X or some other letter. That seems to have disappeared and this one's serial number starts with 87108 with the 87 being the factory and the 1 for the year and following two digits being the week (you know this but that was for others reading). So that does not help.

Now, and your mention of being very conscious of using the phone. I can say that when I have had this problem - and it is very sporadic - I have not been very conscious at that particular time of what I am doing. When this happens in my apartment or study (the vast majority of time I am using the phone) I walk around like crazy going from room to room, light to dark and I know that the phone is moving around my ear and the side of the head a lot.

Almost every single time I have stuck the person on speakerphone (once mute but rare) I have seen the screen light up from the corner of my eye. That indicates to me that, to have to make a poor joke, I am not "holding it right". Can you try yourself and, assuming we have similar peripheral vision, see if you can see your screen? I can't when I put the phone to my ear in a way which I think would be proper.

Another couple of points is that I have had Call Guard for over a month. I have used it probably only 10-15% of the time but never had an instance then of the speakerphone being activated (it would also show as a touch on the Call Guard screen). I also do not believe that when I am sitting at my desk and talking like a "normal person" 🙂 I have had this. It always seems to happen when I am not expecting it and caught off guard.

So I am reluctant to go back again to the Apple Store and get another phone and have the same problem. I am wondering that my phone when it has the problem is perhaps a result of the sensor not being parallel to my face but at an angle. An example; I am in my study and it is almost all dark except my dimmed desk lamp and the monitor glowing. The sensor is not parallel to my check but turned away at say a 30 degree angle. Light reflects off my face and hits the sensor.

One other point, and I saw this mentioned here or on Macrumors is that one individual had this issue whenever he had initiated the speakerphone either at the beginning of a call or some other time. I DO know that the majority of the time, as soon as I dial a number I immediately put the call on speakerphone until the person answers. Could this be a factor?

Finally, I am thinking that I must discipline myself to use Call Guard all the time or alternatively, and I know it is difficult, make a very constant effort to always hold the phone in the "correct way" and not be continually walking around.

A plan or do you think I should play the crapshoot and try and get it exchanged again (which is a pain).

I guess anything could be a factor. Only a heck of a lot of testing or other people reporting would show it if is.

When I was into seriously checking for problems in normal use, I had to turn the brightness all the way up - that way in my apt my eye would be able to catch it if it came on. Normal level, I might not notice unless I was kinda moving my eyes to the side to look at it, which was too annoying.

I'd say using the Call Guard, at least for awhile, to see what results it gives would help - especially in those situations where you say it happens the most.

I think the serial number is (was) changed to show it was refurbished, but I don't know if the information on the date is part of that change.

Are you sure yours is refurbished? I know when I exchanged early on, before there even were refurbished ones available, the stores had a stock for replacement anyway that were in a black box.

While I can get the distance on my phone down to 1/4 inch or even a bit less, the only time I've had it come on during a call is when I try to hold it on my shoulder. And I tend to hold it at an angle off my face otherwise too but it stays off.

I'm just aware of when I move the phone off my ear. This is almost always for comfort since it gets annoying keeping it pressed, even lightly, against the ear for a long time. So, I'll periodically change ears or even just lift it off and set it back on. Those are the times I'll remember that I may be creating the problem and I'll lift it off again, extra far, for a few seconds to be sure it resets.

You might, when doing the test even though it doesn't get as low as mine, try moving it further away and see if yours resets to around the original distance.

Hi again dbk9999,

Regarding the serial number issue, I do know that refurbished phones used to start with 5k. Now, from various macrumors posts, you cannot differentiate what is new and refurbished by the serial number as, when a phone is refurbished, the first 2 digits represent where the phone was refurbished or where it was built initially (my current phone starts with 87 which is the factory serial number) and the date is changed in the case of a refurbishment to show when it was refurbished.

This one is my second replacement iphone 4, the previous one being replaced in December and that too had as the first two digits a known factory number. In that case too the serial number production/refurbishment date was a mere few weeks prior to my being given it.

One other bit of anecdotal information I have found with myself is that the incidence of proximity sensor issues declines markedly (but not necessarily completely) when I go caseless. Now I know this begs the question of whether the case itself's cutout is very close to the proximity sensor. With my case , griffin motif, there is no cutout for the sensor as the case is quite minimalist and covers the back and side and only has a very tiny lip covering the very edge of the screen.

So why does the sensor seem to work better in my case without a phone. I say it again, I think it is the capacitance of my hand which somehow makes it work much better. I really don't know why there is this noted difference between my using a case and not using one.

I am also thinking that if I return this for another phone I might have the same problem again because there is something with the way I make calls that will almost assuredly make this iphone 4 proximity sensor not work properly.

One last question, am I correct in stating that with your current iphone 4 you can, in normal usage but with a given set of circumstances, make your cheek put someone on speakerphone or put them on hold?

Message was edited by: ticksg

I don't like the number being changed to show the week it was refurbished - especially since all my tests have shown phones prior to a certain week failing and all after that week passing. If I made an exchange, I'd feel better if I knew the phone was originally made after that week.

As for my experience, since I know how to avoid the problem, the only time I've actually had the screen come on was if I tried to hold it on my ear. However, I never actually activated any buttons because I've only rarely put it in that position and when I have, I tried to make it very brief.

Very recently, I had my iPhone 4 replaced for an unresponsive home button that would randomly not respond to commands.

The replacement iPhone 4 I have now is having issues with muting/holding calls, randomly going to speakerphone, and--this one is really strange--turning on voice control when I hang up a call.

I called Apple and they recommended restoring the iPhone. That same day, the iOS 4.3.1 came out--it hasn't fixed anything.

I was running iOS 4.3 on my previous iPhone 4 and didn't have any of these problems except for the home button issue. I'm taking it to the Apple store this weekend and going to have it exchanged. If the third time isn't a charm, I'm going to ask for a refund.

texasiphone wrote:
I went to my Apple Store over the weekend to have them look at my proximity sensor not working and the "genius" verified the problem and promptly replaced my unit. However, he did not check it and I later found that it still does not work.
Not only that but I found that after syncing, I did not recover all the information and much was lost to my bitter disapointment. I guess I am going to have to go back again but next time I was have the so-called "Genius" show me that it actually works.

What you can do also is when you do get it replaced, before you walk out of the store, do some test calls at the apple store to ensure that it is working. Use the apple store demo iphone and call your phone. Or just call your friend or whatever at the store with your phone and make sure it works.

Update.

I took my iPhone 4 to the genius bar on Sunday. The "genius" was less than sympathetic. I explained that I had already restored the iPhone, contacted Apple customer service, and the issue still persists. He said that it sounded like a software issue and that "software...isn't covered under warranty." HUH?!

He said he would exchange it as a "one time coutesy" -- gee thanks, it's not like I have a warranty on your stupid phone!

I love the phone but I'm quite frankly tired of their snotty employees.