Restore your iPod with iTunes (warning: this will delete any songs and data from your iPod, so be sure your data is backed up on your computer first).

Disconnect and reconnect the hard drive and hard drive connector. Sometimes the connecting can come loose and just needs readjustment.

Replace the hard drive connector. These are much cheaper than hard drives, and can be purchased in our iPod parts store.

If all else fails, most likely your iPod will need a new hard drive. [Note: if your iPod is a Nano or Touch iPod, the memory is stored in flash and there isn't a "hard drive" in the iPod. In this case, your entire motherboard will need to be replaced.]

Plug your iPod into power and let it sit for at least 30 minutes.