iPhone 3GS 4.0.1 Fail - Power Off Automatically

[sacrin007]

Today, my 3GS (4.0.1, 05.13.04, newer bootrom) turned off arbitrarily. I turned it back on and continued using it. After 15 minutes, it did it again. Then, it started turning off by itself repeatedly, almost instantly.

I rebooted 4.0.1, but have apparently lost my ATT sim card so haven't been able to use it yet. However, I noticed that when I unplug the phone, it turns off again after a minute or so. When I leave it plugged in, it seems to stay on.

My battery was about 60% when this all started. It shows about half a meter now.

Am I in trouble here? Or is it more likely software?

Oh, yeah, I replaced the battery about 4-5 months ago. I haven't had any hardware problems in that time.

Just plugged it back in, and it seems to be turning off and on about every 5-10 seconds at the apple logo.

Help!

OK, found my sim and got my phone set back up... but it doesn't stay on without being plugged in! The battery is at 90%. Now what? Anyone?

[g4geniuses]

Well, you might have gotten bad battery. Or the connectors in the phone which you place the battery on are bad. You could try restoring, that might help.

[Jcbzr]

First, try to do a hard-reset (press and hold the power/sleep button and the home button for 10 seconds).
If it still persists, let the battery run empty, then charge it. That might fix the problem (this solution solved the identical issue I previously had with an iPhone 3G).
If that doesn't work, I would recommend you perform a fresh restore... In the worst case, you can upgrade to 4.2 firmware if you have the SHSHs saved.

[sacrin007]

I have done a soft and hard reset. I have also just done a fresh restore. Still problems. The battery drain and charge sounds like a good idea. Only one problem there: my phone wont stay on long enough to drain the battery! Ideas on that?

4.2? On a 3GS with new bootrom? Can't do that. I need to unlock for my network. Also, I have been running 4.0.1 for 5 months now. No reason it should not work now.

Worse case scenario, I have a new spare battery. I hate changing the battery!

[Jcbzr]

I have done a soft and hard reset. I have also just done a fresh restore. Still problems. The battery drain and charge sounds like a good idea. Only one problem there: my phone wont stay on long enough to drain the battery! Ideas on that?

4.2? On a 3GS with new bootrom? Can't do that. I need to unlock for my network. Also, I have been running 4.0.1 for 5 months now. No reason it should not work now.

Worse case scenario, I have a new spare battery. I hate changing the battery!

Does it keep looping or does it just stay on the Apple screen until you have to hard-reset it?

You can preserve the baseband with a custom firmware via Pwnagetool. Firmware 4.2.1 is known to have fixed battery issues that 4.0 did not (my 3GS had huge battery issues with 4.1, but after upgrading to 4.2.1 the battery issues were resolved).

[sacrin007]

Update: I restored last night, and managed to run the battery to 0% today (after several automatic shutdowns) by leaving a GPS program running with the screen on - apparently leaving the screen backlit keeps it from turning off automatically. It is doing a full recharge right now. That makes me think it is software related, or could it still be related to the battery?

You can preserve the baseband with a custom firmware via Pwnagetool. Firmware 4.2.1 is known to have fixed battery issues that 4.0 did not (my 3GS had huge battery issues with 4.1, but after upgrading to 4.2.1 the battery issues were resolved).

Now I remember why I didn't do this. I need an untethered unlock. My work requires me to be without a computer for several days at a time, can't afford to be without a phone if it turns off or resets.

[Jcbzr]

Now I remember why I didn't do this. I need an untethered unlock. My work requires me to be without a computer for several days at a time, can't afford to be without a phone if it turns off or resets.

What do you mean by an "untethered unlock"?

Your baseband affects your unlock capability, not your firmware (although the firmware can upgrade it).

I am assuming you have an untethered jailbreak with an unlockable baseband, right? If so, there shouldn't be an issue using a custom firmware that will preserve your baseband while upgrading your firmware.

I don't believe it's a hardware issue.

[sacrin007]

OK, so it went from 0 to 100% charge in about 1.5 hours. It turned off after charging it. I turned it back on while still plugged in. As soon as I unplugged it, it turned off. Battery, right?

[Jcbzr]

OK, so it went from 0 to 100% charge in about 1.5 hours. It turned off after charging it. I turned it back on while still plugged in. As soon as I unplugged it, it turned off. Battery, right?

Perform the battery change, tell me if anything changes.