- Try another cable. Some 5G iPods were shipped with Lightning cable that were either initially defective or failed after short use.
- Try another charging source
- Inspect the dock connector on the iPod for bent or missing contacts, foreign material, corroded contacts, broken, missing or cracked plastic.
- Make an appointment at the Genius Bar of an Apple store.
I would start with
Run this to help if it identifies the cause
Have you tried on another computer to help determine if you have a computer or iPod problem?