I replaced my Ipad 2 battery, but it will only turn on or run if plugged in. I think the replacement battery is no good. It's acknowledging the battery there because it won't turn on without the battery installed, but once it's unplugged it shuts down. It shows it's plugged in and at 100% but just plugged in not the charging symbol. works 100% perfectly as long as it's plugged in so that's why I think the replacement battery is bad. I double, triple, and quad checked all the wires and connections. Everything is connected correctly and nothing appears damaged. any ideas?