Q: I have a fourth-generation 20GB iPod. After trying to do a restore on it, the adapter icon showed up and does not disappear no matter how long it is charged in the outlet. What can be done to fix this?
A: Unfortunately, the fourth-generation iPod models needed to be connected to a 12V FireWire power source in order to complete the restore procedure. The likely situation here is that your particular power adapter is USB-based, and only provides power on the 5V pins, which the 4G iPods did not recognize as a valid power source for restore purposes.
Note that the iPod does not need to be charged for any length of time from the 12V FireWire power source—you merely need to plug it in for a minute or two so that it can complete the restore procedure while connected to external power.
The only way you’re going to be able to solve this is to find a FireWire power source, either in the form of a charger or a powered FireWire port on your computer. The charger that came with your 4G iPod originally would have been FireWire based, so if you still have that around and it works, then this would be your best solution. Some other third-party accessories such as speakers and car chargers also still provide 12V FireWire power, so if you have other speakers or docks around it might be worth trying those to see if this allows the restore operation to complete. Speakers that are out on display at your local consumer electronics store would be worth a try if you don’t have anything at home—the original Bose SoundDock is still sold in many places and this definitely provides 12V FireWire power. If you leave near an Apple Store, the folks at the Genius Bar may also be able to assist you with this.