Does the manufacturer say it will work with your model iPod and it iOS?
- 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 still problem, make an appointment at the Genius Bar of an Apple store. Bring the dock
Is the 4G fully seated in the dock? The case configuration of the 4G is different than earlier iPods and the 4G will not fully seat in the dock.