. Toggle the hold switch a couple of times.

2. Hold Select and Play until your IPOD enters Disk mode.

3. If it is not already plugged into your computer, plug it in now, and let it charge for twenty minutes to an hour.

4. Reset it by holding menu and select.

You should now be able to access it again, and charge it up via your USB cable no problems

7/13/23

If the above fails, replace the battery:

iPod Classic Battery Replacement