iPhone 3GS randomly shuts off and won't stay on until plugged in

[zphone]

Some ideas

I have a good amount of experience with repairing iPhones so here is some input regarding the turn off problem.
1. The most likely cause is the battery especially in an older phone. The battery can age in a way where it appears to be charged but has very little ampacity. When the phone attempts to do an operation that requires too much current the voltage drops and the phone reset circuitry kicks in. This is why phones start resetting at increasing levels on the charge display as the condition of the battery continues to degrade. The charge measurement circuitry of the phone would not be able to distinguish this problem. If you look at the customer forums on Amazon you will see that a fairly high percentage of the replacement batteries have problems. The equipment manufacturers (such as Apple) test for this by running a load test so it is fairly rare to see a problem with a new phone. If you buy a replacement battery for something like $5 I seriously doubt that it was load tested. Battery replacement can be done DIY but do not assume that it is easy. There are many parts that interlock to pass signals so it essential to be exact. The video of the girl carelessly popping things apart is very misleading. The touch screen connector is tricky and be extra careful when removing the port connector as there are delicate parts right next to it that can be damaged. If you follow the forums there are plenty of posts regarding problems that resulted from careless repairs.
2. Internal connection problems caused by liquids or other contamination. There are many connection points for power feeds that rely on simple pressure contacts. The phone is not liquid tight so situations that allow liquids into the phone can contaminate the connectors and foul the distribution of power. BTW the primary battery connection to the mother board is is made by spring contacts against circuit board pads. Moisture contamination is probably the 2nd cause of iPhone problems after broken screens. The symptoms of a bad connection can be exactly the same as a bad battery due to series resistance.
3. The last likely cause is a faulty on/off switch. A faulty switch (it gets pressed a lot both intentionally and not) would be the same as intentionally turning the phone off.
I hope this helps.

 

[zphone]

More about DIY battery replacement

I read my previous post and decided it was overly negative regarding DIY battery replacement. Anyone who is reasonably adept at precision work can replace the battery. Just take your time and pay very close attention while taking it apart. Work over a secure surface so you don't lose any screws and keep the screws in order. Magnetize the screw driver to help with this. Buy a battery from a vendor that has high user ratings but accept that the odds are about 40% that the first one won't work. A new battery should be cycled to discharge and charged a couple times before it will achieve its full power capacity. Batteries are advertised that have 1200mAH and 1600mAH but I have no data to confirm that these numbers are accurate or that there is more capacity in the 1600. The chemistry is the same and the battery has to fit in the same space so I'm dubious.

 

[Kashika]

That was very helpful!

I guess I'll get a new battery.

 

[pythonz]

Solution

In my opinion it's a problem with battery. My phone 3Gs (3.1.2) turned off when battery was about 80-90%. When i put phone on charger ir works just fine. What i need is to change a battery, but i did small experiment. I put my phone (switched off) into refrigerator where temperature is -16. I kept it for one night, phone was rolled in paper and covered with plastic bag to keep it dry. When i took phone out, i waited until reaches room temperature and then plug into charger, it was only 6% of battery left (turned off on 85%). After fully recharged it works already for 4 days and got about 44% of charge (worked in standby mode, several calls, 30-40sms'es). So take a shoot, maybe it will help you. But remember, i am not responsible if something goes wrong ;] Let me know if somebody tried also this P.s it won't help for long...
Best wishes from LT.

 

[Kashika]

While I agree that it might be a battery problem, my iPhone crashes when plugged in as well.
Usually when I set an alarm it crashes before my alarm goes off (you see the spinning wheel).

How can a faulty battery cause that if it's plugged in?

 

[dash324]

That was very helpful!

I guess I'll get a new battery.

FYI - I had a new battery installed on my 3GS 2 months ago, and just last week my phone started to shutdown within a minute after it's unplugged. It could be the battery again, but I doubt it since it's only been used for 2 months.

 

[Kashika]

FYI - I had a new battery installed on my 3GS 2 months ago, and just last week my phone started to shutdown within a minute after it's unplugged. It could be the battery again, but I doubt it since it's only been used for 2 months.

That means it could be firmware related. Perhaps waiting for a new update and seeing what happens then is a better idea for now. I can always get a new battery.

Too bad these strange things happen right now

 

[randharma]

Same Problem

Realize my phone is about 20 months old, but I question all these posters joint coincidental update and corresponding shut-down issue?

 

[Kashika]

I think this is one of the issues that came with iOs 5. Maybe it's also why we have to wait so long for a new update (if they fix this obviously).

Maybe more users have the same problem but don't experience it the same way. For example my phone crashes when in standby, but eventually goes back to a lock screen.

 

[dash324]

Realize my phone is about 20 months old, but I question all these posters joint coincidental update and corresponding shut-down issue?

well, this is an online forum where users share information and exchange common experiences, and this particular thread talks about 3GS shutting off after unplugged, what's there to question about?

 

[SuperJam]

https://forums.macrumors.com/threads/1319964/ help me

 

[randharma]

Obviously, battery change worked

well, this is an online forum where users share information and exchange common experiences, and this particular thread talks about 3GS shutting off after unplugged, what's there to question about?

A battery change fixed my 23 month old 3gs, so now I will use it beyond my contract and get a discounted iPhone 5. It shut off just as everyone describes.

Couple of things when changing the battery, have very good light source (sun is the best) and slightly heat the back of the iPhone with a hair dryer to loosen the glue holding the battery in, line up your connections good before applying downward force. Connection #3 is a slide in ribbon connection, very small , make sure up flip up the lock mechanism before pulling it out and be sure it is up or 90 degrees when reinserting, then lock it down. Lay screws out in a pattern and watch the small spring clip that holds the camera down, do not force anything. Just some pointers, and get an online guide like ifixit.com or something of that nature.

 

[JaiKai]

I have the same problem it will turn off after using something like Facebook for a minute or two but now my texts cause it to turn off too. I thought it would be the battery but the strange thing is, I can use the iPod on it for as long as I like even until it runs right down. So this then begs the question must it be firmware related considering it's only certain apps that cause it to crash? It definitely CANT be the battery if I can use the iPod app until it runs down to 5-ish % I plan to make an appointment with a Genius but I don't get much free time since I'm normally doing some sort of work almost everyday, I will not accept them telling me if's a hardware issue with the battery since I have proof that it's choosy with the apps that cause it to cut out, so I will refuse to pay any sort of money to get it fixed. I mean if I'm paying a 24 month contract for a phone that doesn't even work thats just a rip off out of warranty should not affect it being repaired free of charge because why would anyone pay for a service they can't use? It's daylight robbery I believe.

 

[Danny393]

I have had these same problems with my iPhone 3Gs, but slightly worse. It started out crashing only below ~50-60%, and not staying on until it was plugged in again. Later on, the problem got worse. Now, after a few months, it crashes all the time, even once it is plugged in, though I sometimes manage to use it for a few minutes before it crashes again. In the earlier stages of this problem, we sent it in for a free diagnosis of the problem. We were then told that the problem was with the logic board (basically the motherboard, I think), and not the battery. Anyway, that's my story, and I have yet to find a solution (though it's probably to just get a new iPhone).

 

[GROOMERS45432]

Confirmation! Fixed!

My problem was exactly as described on the original post. I read this entire thread, went to batteries plus, after calling ahead to make sure they had one in stock. Drove there, bought a battery (tools came with it... With tax it was $42.00), watched a tutorial on YouTube on my iPad, and followed along.

PERFECTO! Phone is working fine, now.

CONFRMATION COMPLETE!

 

[StewBme]

My problem was exactly as described on the original post. I read this entire thread, went to batteries plus, after calling ahead to make sure they had one in stock. Drove there, bought a battery (tools came with it... With tax it was $42.00), watched a tutorial on YouTube on my iPad, and followed along.

PERFECTO! Phone is working fine, now.

CONFRMATION COMPLETE!

Thanks for the update. So it's been about a month. Has the new battery still solved your problem? Can anyone else confirm their success with a new battery install before I go buy one? I appreciate the poster above sharing their solution but I think one more and a confirmation that the fix still works 30 days later would be very helpful to me and I'm sure others. Thanks everyone.

 

[nikolai101]

Just registered so I could reply here. Installed new battery last night. Everything seemed fine so I plugged the phone in and went to bed. Alarm went off in the morning no problem so the phone stayed on all night. However I noticed that the battery read 48%. I power cycled the phone and it then read 18%! Power cycled again and it was back to 48% but then it shut off. It kept shutting off 3 or 4 times even when plugged into my car charger. Not sure what to try next. I'll do a restore as a new phone but I doubt that's going to help.

Very frustrating especially as a I just paid my carrier to have this phone legitimately unlocked so my girlfriend can use it.

 

[nikolai101]

Problem solved. I replaced the battery which didn't fix the problem. I then tried a restore which wouldn't work due to multiple errors, one of which I tracked down to be a battery problem. I switched back the old battery and managed to get the phone to restore finally. Problem solved! I should have just done a restore to begin with lol. The replacement battery I got looked identical to the original and even had the same part number. The iPhone did not like it however. Beware cheap replacement batteries.

 

[edgeyted]

Problem solved. I replaced the battery which didn't fix the problem. I then tried a restore which wouldn't work due to multiple errors, one of which I tracked down to be a battery problem. I switched back the old battery and managed to get the phone to restore finally. Problem solved! I should have just done a restore to begin with lol. The replacement battery I got looked identical to the original and even had the same part number. The iPhone did not like it however. Beware cheap replacement batteries.

Hi, thanks for your post.
Given that a restore-as-new seems to not have solved this "randomly crashing, requiring external power to boot" problem for many other people, would you mind very much confirming you've still not experienced a reoccurrence of the crashing?

Thanks

 

[nikolai101]

Wish I could but unfortunately the phone still dies occasionally :/

 

[edgeyted]

Wish I could but unfortunately the phone still dies occasionally :/

Thanks for the update, I appreciate it.
I'm trying the DIY battery replacement solution - using a load-tested battery. Will update this thread with the result.

 

[Colonjay]

Try leaving it in a application like iPod. See if it stays on.

 

[edgeyted]

Make sure it's APN 616-0435!

Don't forget: the replacement battery has to have an APN of 616-0435, the 616-0432 batteries are apparently not compatible with iOS4 or greater.

 

[neilem]

Has anyone determined whether this is a firmware or battery related problem?

 

[edgeyted]

Has anyone determined whether this is a firmware or battery related problem?

Well, I suppose in a way it's both:
iOS 4 seems to have made the APN 616-0432 batteries effectively obsolete - hence my earlier post re ensuring one buys an APN 616-0435 battery.