My iphone would only partially turn on when plugged into the wall charger.
Replacement of battery was easy. Took 20 minutes. The online guide was very helpful. Phone is working like new.
My phone would only boot to the logo when plugged into the wall charger. When it was unpluged the logo would fade out. I could not find this problem listed on any blog, so I decided to try the battery change since the Iphone 3 was 3 years old. The new battery worked like a charm.