Revamped version of the iPhone 3G with faster processing speeds. Repair of this device is similar to the 3G, and requires simple screwdrivers and prying tools. Model A1303 / 16 or 32 GB capacity / black or white plastic back.

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Not charging, not coming on?

Hello guys,

I did a little search and found this question/answer. I am experiencing similar problems. One day my iPhone 3GS stopped working. I switched it off to attend a meeting, one hour later tried to switched it back on and the Phone seemed dead. Took it to Apple Store and nothing was resolved and since Apple care expired I had to get a new Phone. Anyways...this was exactly one week ago. I now have a dead iPhone that I'd like to investigate. So, I just opened the whole thing and measured the battery voltage to be 2.65 V. Does this look a bad battery problem? (I am not sure!). I've checked the fuses, as described above and they are both ok . What else? I've noticed that the battery has some kind of logic circuit attached to it. Could it be that, though I still can measure those 2.65 V. I am bit lost now because I was expecting to find a dead battery and it does not seem to be the case. Thoughts? I appreciate

Alex

Answered! View the answer I have this problem too

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Alex, the logic board on your battery is actually what makes it a smart battery, it communicates with the power management IC. The logic board/circuit is part of the single-wire system which stores the battery code and tracks battery readings that typically include voltage, current, temperature and state-of-charge information. Batteries are much more than just a storage device. Anyhow, since you already did your voltage measurements, try to see what you get on your battery contacts when you plug the phone in. Remember that the end-of-discharge voltage for most Li-ion is 3.00V/cell. At this level, roughly 95 percent of the energy is depleted and it will continue to discharge very rapidly if the discharge were to continue. "To protect the battery from over-discharging, most devises prevent operation beyond the specified end-of-discharge voltage." I seem to remember that it is 2.7 volt for the iDevices. If the battery is depleted past that point, it will not charge. there is a way to "quick" charge, or wake up the charging circuit with a 9V battery. There you briefly attach the 9V to the same polarity contacts of the iPhone battery, and it may bump up the charging circuit. So, on a good circuit, I would expect to get a voltage measurement of anywhere from 3.8/4.0V-2.7V You can also try to charge it on an AC adapter. Check on here for the dock connector pinout, as well as some of the voltages that are expected. That way you can see if you have the right voltage coming to the phone.The attached image may just give you something else to measure ;-) So, to make a long story really short, I'd start of with a new battery....:-) Hope this helps, good luck.

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