iPhone 3G / Wifi problem / 4.2.1

I had a problem with the wifi on my 3Gs after updating to 4.2.1. It was clearly not my router because before the update I could see every hotspot in the neighborhood in the list of available networks and after the update I couldn't see anything but my router and the signal was very week.

I searched the internet for a solution and tried nearly everything described with no luck. I turned off wifi because it was slower than 3G and just lived with this for the last couple of weeks. Then much to my surprise after I did a hard boot this morning everything started working normally again. I know I had tried this procedure before but for some reason it seemed to work this time.

I do not have any explanation for this but I thought I would report my experience in the hope that someone else might benefit from it. The problem was very frustrating and I have no idea why it happened (although I suspect it was the 4.2.1 update) and I have no idea why it started working again.

So the only advice I can give is to turn off your wifi and reboot. Try it more than once and good luck.

Here is what i did to make mine work.
went to settings and turned the wifi off and then on
Turned off the iphone by holding down the bottom button and simultaneously holding the top button until the phone shut down. dont use the slide feature when holding the buttons. be patient and the phone will shut down by itself (a hard boot).
i then unplugged my router, modem and micro cell tower..(skip the micro cell if you dont have one)
i waited about 5 minutes then plugged in my modem.
i waited about 5 minutes then plugged in my router
i waited about 5 minutes then plugged in my micro cell tower.(skip this step if you dont have one)
i waited for the micro cell tower to boot up
i then turned on my iphone and low and behold it worked.
hope this helps someone and if it does please post that it did so others can benefit.
Charles

Come on Apple, this is ridiculous!
No word on bad wifi behavior after the update to 4.2.1.
It's so obvious that something went wrong:

I can't connect to my home wifi anymore, have to put the phone next to the router to get a signal.
Did a restore, nothing happened. Same non-wifi connectivity than before!

What's the point of having an iPhone if it can't properly detect a wifi-network anymore?
I wish I could get on the 3G network but that ALSO doesn't work properly anymore. Hallo?!

UPDATE !

Hi think you're getting a bit mixed up there, wifi channel selection has nothing to do with IP addressing at all. The problem people are seeing with updated iPhones is preventing the phone from seeing a network at all. The phone never gets to the point of requesting an IP address. Addressing isn't the issue here at all.

If you check your router in particular the devices connected you will see that an iPhone connecting to a LAN is issued an IP Address this Address should accord with the Ip address displayed in Settings/WiFi Networks. In this screen the Subnet Mask Router and DNS IP Addresses are also displayed. I was suggesting that that you convert the IP address allocated by the Router to the iPhone from Dynamic to Static that way the iPhones IP address is maintained as a constant. In relation to channel selection in my experience I have found that many routers come with Channel 6 as the default setting which could have the effect of creating a crowded space 'to many LAN's using the same default channel' There is some free Windows XP/Vista [not sure about Windows 7] compatible software called Vistumbler 'I have no association with the Developer/Distributor' which allows you to display all WiFi answering points in close proximity as well as the signal strength encryption method etc. I use this software to identify the channel that may provide the best connection. And for other readers it is always a good idea to get the iPhone to forget the network logout the App Store and then cold boot all equipment and bring it back on line in the correct sequence. It should also be noted that Router encryption keys are case sensitive and I have found that if you make a mistake during input requires you to start the encryption key process again. It is also a good idea to check that the firmware on the Router is up to date. Ant..

Message was edited by: adnixon

Specific problem: iphone 3GS which worked fine on my WPA2 wifi before upgrade to ios 4.2.1 now will not connect.

Tried: most of the suggestions in this thread, to no avail.

workaround: the WPA2 key is being correctly processed; it is simply that the dhcp server in the router is not giving out an ip address (timing issue in the iphone software since the upgrade?). by inserting a fixed ip address in the phone (use the Static tab on the wifi settings window) and ensuring that the router reserves that address for the phone's MAC address (so that it does give it to anyone else and create a later problem) i get a robust connection.

<Edited by Host>

Hi Ad,
Yep, appreciate all that it's just your original post suggested that a static IP would also fix the channel. Apologies if that's not what you meant 🙂

Still, of all the iPhones I've seen with this issue the device never gets to the point where it can see the network, let alone connect to it, authenticate and request an IP address. I very much doubt local IP addressing or DHCP are part of the problem. Indeed testing we've done (and the feedback in the spreadsheet) would suggest that the problem is consistent across different AP types, wifi protocol config, channel and authentication setup.

Hi Tom_JB some have reported to have resolved their WiFi issue by reflowing the solder that connects the chip to the board. Sounds drastic but by now it has been reasonably well documented. You will probably find on YouTube a video clip on the subject. Might be worth considering. Ant.. Irrespective of warranty conditions if the phone is under contract to a service provider you may have some consumer protection leverage with the useful life or fit for the purpose argument. In my view in a commercial setting the useful life is probably 2 years or in accordance the depreciation 'tax' write provisions applicable in your part of the world. I consider my iPhones as a consumerable after they have reached the end of their useful life '2 years'. This view may be considered by many to be unrealistic especially those who do not want to sign the cheques. The solution for many does not appear to fall on an issue with the iPhone or any of its iOS upgrades. I think almost without exception every upgrade has been blamed for the loss of WiFi. Unfortunately many have been rather quick to blame the iOS as the point of failure I am yet to be convinced simply because I have 3G 3GS and 4 all upgraded in every version of the iOS when it was published and currently working with 4.2.1 without any issues. Time to think outside of the box me thinks Ant..

After I got back home yesterday from visiting family for the holidays my WIFI decided to stop working. It worked just fine before, I did the update while I was away, and when I get back home its messed up. It is saying in my settings that it is connected (I put in my password and everything), but at the top of my phone it says 3G instead of the wifi signal. Which is causing me to be unable to facetime. I have reset my router, my phone, turned off the 3G network...I've done it all! I dont know whats wrong and what I can do, but I need it to start working soon!! Please help...

just got phone, my phone works on my router at home, but doesn't switch over to 3G when there ISNT'T a suitable wifi

what the ****? i bought this phone because I hated all the other phones i've had!

is there any resolution to this or do i have to return this thing now too???

Contact your 3G Service Provider

I don't think it's that simple, Tom, because feedback in this thread is actually showing a multitude of differing symptoms. This includes failure to even identify an available Wifi network as you have described, but also identifying the network and failing to connect, indicating that a connection has been struck but refusing to pass any data over it, poor performance, and random disconnections.

What is even more curious is the murkiness around the root cause:
- Most have naturally assumed that the upgrade to iOS 4.2.1 has caused all of these issues, but there are dissenting opinions from people who have experienced problems with older iOS versions.
- When I first joined this thread I got the impression that the problems affected only the iPhone 3G, but I have major connectivity problems with both my 3GS and my iPad.
- Some are suggesting that a hardware fault in the antenna soldering is to blame, but this seems unlikely given that the problems appear to be occurring on a variety of devices (i.e. differing iPhone generations + the iPad).
- Although problems are widespread they are probably still only affecting a minority of users are we haven't seen a huge public outcry yet.

I am personally tending towards thinking that there may be multiple issues affecting connectivity on iOS devices, with individual users being affected by one of them, more than one of them, or none of them, depending on their particular device, iOS version, and network configuration. This needs some serious investigation.

Thanks Charles. Your solution worked for me.

Kia Ora alasta22

I have not had any issues with 4.2.1 with either my iPhone 3G, 4 or iPad so I am one with a dissenting opinion that it is the iOS. For your information my iPad is a 3G+WiFi Version 4.2.1(8C148) Model MC497X Modem Firmware 07.10.00. If you have the same beast then I would be looking at the answering point as being the point of failure. My answering point is a Netgear ADSL/2 WiFi Modem Router 54 Mbps DG834G v5. The service provider is Optus. The firmware on this Router is Version E25.41.44A which is automatically updated by Optus as an Internet delivered service as and when required. Expat Ant..

actually i was mistaken. my phone IS working....4.2.1 as well.

its just that a wifi popped up for me to join, and i tried, but it was not 'trustworthy' so it said, so i couldnt join it, and then i THINK i had to go turn OFF wifi in order to use my 3G...but just that once...

today, in numerous instances, i was on wifi leaving my house, and then instantly on 3G elsewhere...

so its working!!!!