First try another charging source. Maybe the source yo are using is not putting out enough pwere when the screen is on.
- Reset the iOS device. Nothing will be lost
Reset iOS device: Hold down the On/Off button and the Home button at the same time for at
least ten seconds, until the Apple logo appears.
- Reset all settings
Go to Settings > General > Reset and tap Reset All Settings.
All your preferences and settings are reset. Information (such as contacts and calendars) and media (such as songs and videos) aren’t affected.
- Restore from backup. See:
- Restore to factory settings/new iOS device.
If you restored to factory settings/new iPod and still have the problem that indicates a hardware problem.
- Inspect the dock connector for bend or missing contacts, foreign material, corroded contacts, broken, missing or cracked plastic.
- Make an appointment at the Genius Bar of an Apple store..