I just purchased a troubled 3G 16GB and i'm getting an Error 23 when trying to restore. I understand this is a radio error / baseband problem which should be fixable by restoring.

However, I believe there is also another problem which prevents me from restoring. The phone will not charge or power on by itself. If I plug it into the computer via USB it powers on. I get the Apple logo for a bit and then after a while it goes off.

I can put the phone into recovery mode and I see the logo indicating that I need to plug it into iTunes. I can also put the phone into DFU mode.

As soon as I unplug the phone from USB power it immediately goes off.

My theory is that since I see the Apple logo that it probably isn't the logic board. Hopefully, I just need to replace the battery.

Can anyone confirm or reject my suspicions?

if the phone powers off once the power supply is removed then it is most deffinately the battery.

Hope that helps

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UK iPhone repairs, 2G | 3G | 3Gs

Sounds like a water damaged phone. You probably have a fried resister or something somewhere along the power circuit. I revived one phone with such a problem by bridging the trace where the blown smd was. Check the smds close to where the void sticker is. I wouldn't be surprised if one or more of those components is fried.

Neither water damage indicator was red and the phone clearly had not been opened. When I opened it I hadn't seen any evidence of corrosion or water damage. I have just replaced the battery. I'll let it attempt to charge for a while and see what happens.

Can you provide more specifics about "bridging the trace where the blown smd was"? I would greatly appreciate it.

A fresh battery should have enough of a charge to power on the phone. If not, it should not take more than 15min for it to build enough charge to power on. Hopefully, it is the battery (although doubtful in my opinion).

If the phone had not been opened, and there were no signs of water damage (indicator in earphone jack, and under dock connector, as well as the 2 indicators on the mainboard), then your phone should still be under warranty. So unless your phone was purchased from a different country than the one you are in now, you should be able to take it back to Apple for warranty, assuming you purchased it after today's date last year.
This would be your best option.

If there was no water damage, then it's probably not like the situations I've encountered. Still, have a close look at the mainboard, and see if there are any signs of any of the smds being fried. If not, then I don't think I can offer much useful advice. Troubleshooting the mainboard without the proper documentation and technical skills is next to impossible.
If a dfu restore gets you nowhere, you're probably sol, unless of course you are covered under warranty.

So i've taken a deeper look at the logic board near the void sticker as suggested and i've compared it with another phone. Clearly there is some indication that something has blown. 2 of the 4 circular gold contacts in that area are darkened.

However, I have also compared the inside of this device to a water damaged phone and I firmly believe that it isn't water damaged. The water damaged phone I am looking at has all sorts of gunk and corrosion on many pieces of the connector ribbons and such. I have salvaged the LCD/Glass/Digitizer assembly out of this phone and it works great.

My theory is that someone plugged it into a charger that they shouldn't have and it fried the area mentioned by tony604.

Unfortunately the dude I got this from had lost the SIM card and thus the serial number so I don't know if it's under warranty or not. But seeing how i'm using a couple of these devices to learn how to perform repairs and replacements I'm wondering if everything but the logic board is good.

In cases where an unapproved charger has been used is the damage I am seeing consistent with such cases? If so, how much of the rest of the phone should be okay (ie. dock connecter, switches, headphone jack, etc)?

Finally, my last electronics class was about 15 years ago but if I can remember what "bridging the trace between the blown smds" means I'll give that a shot too.

The serial is inscribed into the sim tray, so as long as you have that, you're good. The sim itself is meaningless for warranty purposes.
All other components should be good still. Mind you, that doesn't actually leave much. The whole phone is basically the motherboard. The housing can be used if still in good condition as well as the earphone jack/ button assembly, dock connector/speaker/mic, and most probably the camera as well.
Once a smd component fails, conductivity in that trace will stop at the point where the faulty component is located. Bridging the trace literally means bridging the trace. Simply use some solder (bridge) to restore conductivity to that particular trace. Or do a proper repair and replace the damaged smd.
I've not heard of any accessory damaging 3G/3GS phones (short of surges or lightning strikes I suppose). There was a problem with 2G phones and accessories that charged by the FireWire pin, but Apple has disabled FireWire charging on 3G/3GS phones. Have you noticed that some accessories will not charge 3G phones?