iPhone 4S dropping network and data at random

Hi,


I've been using an iPhone 4 on a Vodafone contract for the past 16 month and just bought an iPhone 4S direct from Apple. It arrived on Friday morning and I got it set up correctly as far as I can tell.


When I first turn it on, it works lovely and exactly as I would expect, able to make calls, send texts and access the internet via the cellular network. However, at what appears to be random, the network will disappear (no bars of signal) stopping me making calls and texts, but still allowing me to access the internet. Sometimes, the Internet goes, but I can still make calls and texts. Other times, everything is gone and I get "No Signal" where it normally says Vodafone UK.


So when trying to fix this problem after it's noticed, I try putting it into Airplane mode and back out. The phone scans for a network and goes back to the same state as before I tried this fix. I have tried resetting network settings, but this doesn't change anything. The only thing that actually fixes it temporarily is turning the phone right off and back on again.


At this stage I assume this is a bug with the software, but I wondered if anyone else is experiencing anything like this? If no one is, I will take it up with Apple, but I don't really want to do that as I love the new phone so much!!


Cheers, Stuart

iMac (late 2009), Mac OS X (10.6.3), 27" i7 Quad-Core, 4GB RAM, 1TB HDD

Posted on Oct 16, 2011 2:53 AM

Reply
1,022 replies

Jan 26, 2012 12:34 AM in response to Blowdesign

hello,


i believe the two letters at the end of the model no are some kind of localization difference,so there might be a difference in the american,british and some european types etc...just guessing


you'll find the type of your sim as follows:


settings-phone-sim applications-sim status


it will show a black screen and on the top it will say:


smart sim 128a (this is my case,you will have something else i suppose)

under that some more digits...


as you will hit the sim status button it might not respond at first so hit it again and again till it shows the black screen...


just to note,when i did have the network drops,i was not able to get through there,in fact i was using the responsiveness of the sim to the status request as proof that my phone is not in the network,had to restart the phone to get there...


also there are more models of the 128k sim the letter "a" at the end of mine is the model signature,i did see other models with letters "d" "e" ...

it might be that it does not work with all the 128k sims,just with the latest ones


but i definitelly believe it is not hardware related,and that this is and issue of iphone working only with a small number of latest sims,whych by the way is totally silly from apple if so...


good luck

Jan 26, 2012 1:39 AM in response to Blowdesign

alright,so you do not see sim applications menu when you scroll all the way down? interesting,there is the answer to the model nimber difference then...


ok,when you got your sim,did you keep the big card from whych you pushed your sim out?it has your puk and bpin on it. ypu should have some long nimbers there and it will end in the way 64e or 128a (the letters may vary)...try that,or go to your providers shop and have them to check it out for you...

Jan 26, 2012 2:59 AM in response to Blowdesign

i just tought about it...how old is your sim? is it the smart sim? you might not have the sim status menu because your sim is not supporting it...


i am still convinced that this is sim related...


can i ask those of you who replaced the sim for 128k one, and problem remained,what letter is after the 128"x"?


i got 128a and i am good since i got it...


cheers

Jan 26, 2012 11:01 AM in response to Stuart Mchattie

Ok, Im listing ALL the solutions so far discovered towards the problem.

1. Swap Sim (try 64K or 128K sim card) ----- Success rate - 54%

2. Disable Sim Pin ----- Success rate - 83%

3. Switch off Call Forwarding, Call Waiting and switch on 'show my caller ID' ----- Success rate - 66% (including myself)

4. Make sure your MicroSim is properly cut/made. Success rate N/A

5. Upgrade to 9A406 ----- Success rate - 70%

Jan 27, 2012 5:08 AM in response to Stuart Mchattie

Hello everyone, here is my experience with the iPhone 4S with dropping network and data at random.
I bought my iPhone 4S 32 Gb with firmware 5.0 in early December 2011 and had no problems.
My phone Carrier is WIND Italy.
The dropping network is started in a sporadic and random when I updated to firmware 5.0.1 (9A405) with "NO SERVICE" on display then "Locked SIM".
Thinking it was a problem with the carrier WIND I immediately replaced the SIM with another new one.
The problems are not resolved.
Upgrade to iPhone firmware 5.0.1 (9A406)
At random, and not infrequently I can't make phone calls, SMS, web operations.
Recall carrier WIND and perform the verification tests with the SIM observing that when the iPhone switches from 3G to EDGE and vice versa, is not able to return to the BTS (antenna) 3G automatically.

So they change HLR cluster position in SIM for detect it in another position in the BTS.

Same issue.

So they ask me to try the same test, with the same SIM, with a Nokia E65 in both modes (automatic and manual 3G - GSM automatic and manual).
The Nokia in the same coordinates and with the same BTS had no problem. It switch automatically fron 3G to the Edge or GSM mode without issue.
Then I tried my SIM in another 4S 16Gb iPhone firmware 5.0.1 (9A406) and everything worked regularly in the same geographic area and with the same BTS.
I then tried again with my SIM in another one iPhone 4S 16Gb 5.0.1 (9A405) in the same geographic area and with the same BTS: No problem.
I decide to go to the Apple Store yesterday afternoon.

I explain the problem (they said not to be aware of the problem) and ... : They replaced the iPhone with the same model and same firmware 5.0.1 (9A406).
Now i use from 22 hours the new phone and it works fine without issue.
I cross my fingers in the hope that is not present the same problem in the future.

At this point I think, for the moment, that some models have hardware problems.

I suggest to go the Apple for check your model.

Regards

Jan 27, 2012 5:33 AM in response to m.rega

hello,


well exactly that would be nice if you would have posted also...your model numbers of the original returned phone and the new one...so we could relate to and narrow down solutions individually...


anyway still do not believe it is a hardware problem,as everybody is saying that the problems started after updating to 5.0.1 from 5.0....unless the software update could have damaged the phones hardware...whych is very unlikelly...


or the code of the update could have been messed up by apple,why not.


i did have issues and have them no more after a new smart sim128a.


all our cases are different and it can be what i believe it is a combination of problems related to the sim card type and the way the iphone wants to use the network after the update and what it is allowed by the network...and the fact that i use it on a network whych is not officially carrying the iphone.my mums card (the iphone was her upgrade) worked perfect when tryed...in her network.


so if my mum was to keep the iphone, we would not even notice something is wrong and i would not be typing this right now...


cheers

Jan 27, 2012 7:17 AM in response to Stuart Mchattie

Hello guys,

today I went to take the new micro sim card from another carrier I will try it later and update to tell u is this solution worked or not.


I posted here that u should turn off all the 3g settings, and today I turned on the celular data and my phone is working, again how long will see this is totaly unpredictible. It's like he's screwing with me now it's working and I just got my new micro sim from another carrier to try it 🙂)))


As I can see from many I concure with jurajpe that is not the hardware problem or malware. In this case probably u would have a much different problem with signal or something else on the phone and it would be recognized much eaiser, u would not have signal at all or some error that's def. The best argument is the new update, this pages were empty cause nobody had problem when update arrived boom.



As a conclusion I wish to everybodu to solve the problem...


Cheers

Jan 27, 2012 12:47 PM in response to jurajpe

Ok. @Jurajpe

For privacy i'll don't paste there the two model number but i'll report the result of it analized by there :

http://www.chipmunk.nl/cgi-fast/applemodel.cgi

You can try for every iphone.


the first one buyed is :

Name: iPhone 4S

Model: iphone_4S

Group1: iPhone

Group2:

Generation: 6

ModelCode: iphone_4S

Machine Model: iPhone4,1

Model introduced: 2011

Production year: 2011

Production week: 44 (November)

introduced test: GOED

CPU speed: 800MHz

Family name: Become a pro user to see this information. (sorry)

Screen size: 3.5 inch

Screen resolution: 960x640 pixels

Colour: Black

Capacity: 32GB

Factory: DN (China, Chengdu - Foxconn)


the new one is :

Name: iPhone 4S

Model: iphone_4S

Group1: iPhone

Group2:

Generation: 6

ModelCode: iphone_4S

Machine Model: iPhone4,1

Model introduced: 2011

Production year: 2011

Production week: 53 (January)

introduced test: GOED

CPU speed: 800MHz

Family name: Become a pro user to see this information. (sorry)

Screen size: 3.5 inch

Screen resolution: 960x640 pixels

Colour: Black

Capacity: 32GB

Factory: DQ (China)


So you can see that the first on was built in Foxconn in week 44 of 2011, but the new one was built in China in week 53 (January).


I don't know wich is the difference !

regards

Jan 27, 2012 1:16 PM in response to m.rega

hello,


wow!!!that is way too much info.lol.i did not mean to go that far mate.


my model is MD235CS,that is what i tought,i believe its the same model for everyone purchacing in central europe...,


orher info good to compare is modem firmware, which in my case is 1.0.14...


that is where i am going with all this,when people go for a replacement,maybe they get the same model,but the firmware is downgraded if identified by apple as the source of the problem...or some other instance...


so i am good now without drops 100% performance and i am running


iphone 4s 16gb black

MD235CS - model no

1.0.14 - modem firmware

ios 5.0.1 (9A406)

O2 svk smart sim 128a


prior to the sim exchange i was on


O2 svk smart sim 64e


rest the same and i had


!!!constantly!!! no sim/sim failure/out of reach. no phone only ipod basically

so as it sounds to me not all models play nice with all carriers...sad but true...


cheers

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iPhone 4S dropping network and data at random

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