The Apple iPod personal media player uses a set of symbols to communicate what's happening to the device: when it needs to be recharged or when it's experiencing problems. Sometimes it's not obvious what these symbols mean; problems with your iPod may cause conflicting or confusing icons to be displayed.
Folder with an Exclamation Mark
This suggests that your iPod can't read data stored on it. Your iPod may simply not have enough charge in its battery to read its hard drive. If recharging it doesn't help, you can try connecting it to your computer, then updating it with the latest version of the iPod's software. If none of this works, you may have a dead hard drive; your iPod will need to be repaired.
Battery with an Exclamation Mark
A battery with an exclamation mark usually just means that your iPod needs to recharge. Once the battery has charged up again, everything should be fine. You can charge an iPod through a FireWire connection to a computer, but not if the computer is in sleep mode or switched off. Third-generation iPods cannot be charged via USB 2; later iPod models can, however. If you are having problems charging your iPod, try switching cables. You can also try resetting the iPod by pressing Play and Select together (Menu and Play on earlier models). If none of these methods help, your battery may need to be replaced.
If the battery icon shows an empty battery, this means that your iPod is almost out of charge and needs to power up. If you know that the iPod has been charging for a while, and the battery icon is still empty, you may need to update its software. Older software can lead to a confused battery readout.
Wall Plug with Power Adapter
This means that your iPod needs to be plugged into an electricity supply while it updates its firmware. You won't be able to do anything else with it until you do this.
Frowning iPod Icon with an Exclamation Mark
A picture of an iPod with a sad face and x-ed out eyes plus an exclamation mark indicates a very serious problem with the device. In some cases, draining the battery completely then recharging and resetting the iPod can offer a short term solution, buying you enough time to back up your iPod's data. The underlying problem will remain and is likely to get worse until your iPod is repaired.
A brief appearance by the Apple logo when the iPod is reset or switched on is normal and nothing to worry about. If the logo does not go away and the iPod doesn't boot up, there is a problem. You can often resolve this by putting the iPod in Disk Mode and then restoring or updating its software; note that you will lose all data stored on the iPod if you do this. If this doesn't work, your iPod needs specialist attention.
Do Not Disconnect
It is not safe to unplug your iPod when you see this icon. Wait till it goes away, then you can safely disconnect your iPod.
Spinning Disk Icons
The spinning disk and magnifying glass icon means that the iPod is performing a disk scan. If you don't want to perform a scan right now you can reset the iPod; you'll see a disk with a cross when you stop the scan. If you would rather let the scan complete, you should connect the iPod to a power source as scanning drains the battery. If the scan finds issues but can fix them, you'll see a disk plus an arrow. If everything is all right, you'll see a disk plus a checkmark. If there is a problem that the scan disk function could not fix, you'll see a disk plus an exclamation mark.