Hi
The best thing you can do at the moment is use this guide to disassemble the iPod and check things out from the inside
[guide|396|new_window=true]
Check that the click wheel connection are seated correctly and are free from dirt or debris(if there’s is any some isopropyl alcohol and some cotton buds is a good cleaner)
If cleaning the connectors doesn’t help you will most likely need a new click wheel or top case
Hopefully this helps
Any questions please ask
Thanks:-)