iOS4 update - now iPhone now reboots during phone call

Hi there,

Just adding my name to the list of 3GS owners affected by this issue. Same as everyone else - no problems with iOS 3.x.x. Started rebooting the week I updated to 4.1, which I did about a month after my warranty ended (even more infuriating). Continues with 4.2. Brought it into the Genius bar with printouts from this forum. They refused to acknowledge the issue and said my options were to try replacing the battery, or buying a replacement 3GS from them for over $200.

I just tried the suggestion by icehacker - jailbroke using redsn0w, replaced mobilewatchdog with the one from 3.1.2. It had no impact on the rebooting. If anything, it's worse than before.

Nice try but it looks like this really is a hardware problem. I guess I'll try removing the battery and putting it back in next. I'm just about ready to give up on this as a lost cause. I am thoroughly unimpressed with my Apple experience.

Luckily for me, my employer allows me to upgrade once every year for a new customer price, even though I'm on a three year contract, so I bit the bullet and got an iPhone 4. I love it and no problems yet, but based on this experience I expect a mysterious problem associated the iOS 5 will start affecting iPhone 4 owners shortly after launch of the iPhone 5 next summer.

My next phone will likely be an Android based on this experience.

Ephelant, I can't wait for your feedback when you remove the battery and put it back in.
As NIKKOH007 (who came up with that solution) said, you have nothing to loose.
I hope it works for you!

Message was edited by: sb0611

Message was edited by: sb0611

I have to report that after changing the mobilewatchdog file , as suggested by icehacker, at the beginning it seemed not to have worked for me but after some reboot the phone started not to reboot by itself anymore. Don't ask me why, I have no idea about it ......

Message was edited by: Sax412

*PLEASE TRY THE FOLLOWING**

Hello , please try to change the orientation lock to "locked" mode and then do a few calls . I nearly tried EVERYTHING but after I changed the setting to portrait orientation lock ( for unrelated reasons) and leave it like that ,I realized that the phone didn't do a single reboot!

If you have the same results, then the problem we are dealing with is on the proximity sensor!

Message was edited by: panar

Mine is still shutting down randomly 2 days after applying the suggested fix by IceHacker. I also tried the orientation lock suggestion. No effect whatsoever, as suspected.

I will try the battery removal/replacement when I have the correct tools and report back here with my result.

Good luck with that!
This seems to be pretty decent resource for the battery disconnect/reconnect or replacement:
http://www.ifixit.com/Device/iPhone_3GS
Of course, there are many more videos and how-to-guides all over the web.

Hi Everyone I was also experiencing this problem so I tried all the fixes suggested on this forum except removing the battery & icehacker's fix but the reboots were still happening so I made an appointment with an Apple genius. The genius swapped out my 4 week old iPhone without hesitation saying that he had heard of the problem before. Ten minutes after walking into the shop I walked out with a new iPhone. The replacement appears to have corrected the issue as I have made a 20minute phone call with no reboots.

Hi all

I'm new here and i'm glad i found this topic. I was experiencing some very annoying problems with my iPhone 3GS (4.1) lately. Making a phone call had become impossible since it kept shutting down after a few seconds. And even when i wasn't making a phone call, the phone just turned off by itself, unless it was in airplane mode. The modem/antenna seemed to cause the problem. Restoring it to 4.2.1, 3.1.3, 4.0.1 didn't do anything.
So i followed NIKKOH007's advice and now, it's been 2 days that the phone is working flawlessly.

If your phone is out of warranty and you're having this problem, disassemble it, remove the battery, wait several minutes, reassemble it and it should do the trick.

THANK YOU NIKKOH007!

PS. i used this guide ( http://www.ifixit.com/Guide/Repair/Installing-iPhone-3GS-Battery/1545/1) to disassemble the phone, with a small screwdriver and a suction cup.

I'm glad you tried it i am now on my 19th day and still no more problems on both phones.

I had the same problem, and experience. I'm still using my 3Gs however, and I have not decided to take the $200+ repair route.

I suffer from this off-switch from time to time and will try to follow the battery solution. But it was there before IOS4.
But what do i have to do if i (hopefully) got everything together again?
Is it enough to connect it to itunes an get my backup back or do i have to configure some settings by hand?

Just an update on my experience. My 32G 3GS began rebooting 4 or 5 mins into calls after updating to iOS4. It's out of warranty so I took it to the Apple Store in London without holding up much hope. The Genius was very friendly and said she had heard of the issue. She suggested I tried a reset which I told her I had done. She then got a colleague who suggested a full DFU reset which I said I had also done.

At that point she ran out of options and suggested I could either try another reset, which I said I didn't think would help, or pay to have the phone looked at. I politely explained that I thought it was a little unfair that I should have to pay to fix a problem caused by an update Apple recommended.

She and her colleague agreed said they would need to talk to the manager as a next step. He came back and despite the phone being 180 something days out of warranty they replaced it there and then.

Having read some of the posts on here I was really pleased with the service. If I had any advice it would be:

- Try all the troubleshooting tips on the Apple site before you book an appointment, otherwise the Genius will just send you away to do them one by one.

- Backup your phone so you can have it replaced without losing anything.

- Explain (assuming you have exactly the same issue) that the phone was fine until you did the update. My key point was that I shouldn't have to pay to fix a problem caused by an update Apple recommended I install.

- If the Genius can only suggest that you pay for the phone to be looked at, ask for them to speak to their manager as they can override issues of warranty.

- Be polite and courteous at all times! I saw one man shouting and swearing in there and as well as making him look like an idiot, I'm sure it didn't do him any favours with Apple's staff.

- Finally, if I was being cynical, I would say book your appointment when they are very busy - e.g. lunchtime. I had to wait an hour past my original slot and I think the store managers may well be more willing to replace items just to get customers out the door.

I have no reboots since two battery completely run down in november. Some application use data transfer and dry battery, I noticed this in my bill, over 200Mb downloaded.
After this no reboot at all, working like new.

ps. did i got new OS in this 200Mb????? 🙂

I'm experiencing the same issue and just wanted to add my name to the list so Apple will maybe acknowledge the problem some day.

Something I noticed during those reboots: I have a passcode lock whenever I boot the phone, which I put in place for security reasons. Also, I always have to enter the PIN number of the SIM card to connect to the mobile network. But the weird thing is, when the phone reboots during a call (the issue discussed in this thread), I am never prompted to provide the SIM PIN. It just connects. I know it's not much to go on, but maybe this is useful information for someone.

Please read http://discussions.apple.com/thread.jspa?threadID=2544949&tstart=0&start=165
Multiple statements like
"I've had my replacement battery in for about 10 days now...no problems whatsoever. I've done every single thing with my phone that I was doing when it randomly shut down before,(Google Maps, Angry Birds, facebook app, etc.), and it has not randomly shut down even once since replacing the battery. I feel pretty confident in saying that the battery was the problem. Good luck to everyone"
make me believe the battery is the root cause for most issues discussed here. Even just disconnecting and reconnecting the battery could help.