Andrea, the first thing I would change is the battery. It is possible that you kept it alive longer than its lifespan by increasing the amperage of the devices you used to charge it with. The USB port having the least amount of amperage and the car charger the highest. Start there, if you have not had any other damage to it. Keep your dock connector clean, remove any lint etc, check for corrosion and bent pins. I would not think about replacing anything else just yet. Good Luck
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