iPhone 4 signal issue with no bars

I'm having the same issue. Signal goes to "_ _ _ _ AT&T 3G" resulting in no voice, voicemail, or SMS/MMS. It is happening on my iPhone4 and my wifes. It started happening about 3-4 days after upgrading to 4.0.1. Now running 4.0.2 and same issue. It locks on no bars 2-5 times/day. Must power off and back on to recover. Airplane mode toggle doesn't recover.

Sounds like the issue others are having here.

I also have a MicroCell in my home. I was wondering if that was the cause, but it happens in the middle of the day when we are not near it. Looking at the posts here, it seems unrelated.

Also spoke with tech support and got all of the reset and restore options mentioned by others, even the if all else fails need to replace the phone. Looking at the posts it seems the only thing replacing the phone will do is get more attention on the problem that is costing Apple money.

It seems like the signal tower theories have the most plausibility. I'll be watching the posts. But, wanted to chime in that this is not an isolated issue.

Still had the issue today. Stopped by an AT&T store this evening and they replaced my sim no questions asked. We'll see how it goes.

- Chris

I went to AT&T and spoke with a tech there regarding my lock up issue. He checked my area and said that it was on the edge but still ok for coverage. He told me how cell towers work, that they can only handle a limited number of calls and if you're the one over you get bumped right off but you should have two other towers to pick you up. However if you don't have a clear shot at one of the other towers or if they are overloaded then you may never find a connection. The signal may be there but the towers are overloaded and no room for another connection. We already know that the iPhone and new iPhone 4 have created an over load on ATTs networks particularly on already strained areas like the one I live in. Having tried all the tricks and resets including OS 4.0 vs. 4.0.2 and a new phone I'm pretty sure it's an ATT/other burdened carrier issue with coverage and maxed out equipment or it is an OS issue with a problem with 4.0.

Message was edited by: netadmin2010

AT&T cell service stinks, I had issues with my 3GS and the same with 4G, maybe a little better with 4G I'd like to know if other cell phones other than the iPhone get dropped calls. I have Verizon for work phone and while I don't use my Motorola Q as much as my iPhone, I don't get dropped calls. I wonder how much has to do with the iPhone and that issue hasn't been found. I read an article about Apple using a chip in the iPhone that is more used in Europe where cell towers are closer together, when that was brought up to Apple the response was from Apple it wasn't their problem and it was AT&T's issue... Hummm we won't know until other carriers get the iPhone and I hope soon, I would pay the $300 something AT&T is now charging if you jump ship.

Chalk me up as another one with this problem. iPhone 4 running 4.0.1 goes to "_ _ _ _ AT&T 3G" and I can't use voice, but data works. It will stay this way until I reboot the phone. It only happens at home, never happens anywhere else. I was away on vacation last week and the phone worked flawlessly for the entire week. I came back home and within the hour it was back in the locked up state.

Been experiencing this issue as well, hoping iOS 4.1 will fix this. If not then I will be paying a visit to the at&t store.

I've been running it for a week now with 3G turn off, and the problem has gone away. I did try turning 3G back on at one point and the hung up state quickly returned. So it's definitely something to do with 3G.

Oh, and you have to turn 3G off before the problem occurs. Turning it off after you're in the hung up state doesn't fix anything.

FYI, The 4.1 update did not fix the issue.

i have exactly the same problem you guys are reporting.

hi,

any updates on a fix for this problem?

Looks to the 4.2 update…

I hope there will be. C'mon Apple - get your finger out! I'm losing faith as well as my signal!

if they don't fix this, my next phone won't be an iphone.

i had a 3G, a 3GS and it stops on the iphone 4

by the way... antenna gate is a real problem...
it´s ridiculous paying so much for a phone that as so many problems

Any update of the issue?

I have similar issues with my iPhone 4, although I can still make and receive calls when the iPhone 4 shows no bar. And the voice quality seems OK too. But turning off and on the air mode I can get back to 3 bars, which is the normal signal strength.

Also, I notice that this issue is more serious in some days than in others. So it looks like it is 3G network related, although it could be related to ios 4.1 too.

By the way, did anyone know whether having a new sim card from AT&T will solve this issue?

My wife and I are still having the same "_ _ _ _ AT&T 3G" issue on both of our iPhone 4s running iOS 4.2.1 months after reporting it. Has anybody had any luck with a fix yet? I've tried resetting network settings and even completely restoring the phone and starting anew with a clean install, but I'm still experiencing the problem. Switching to EDGE might be an adequate workaround for the time being, but for the price I paid for the phone and continue to pay for the service, I think it is entirely reasonable to demand that this issue actually be fixed with an update.