iPod formatted on a PC can be read by a Mac computer but not the other way round.
So your iPod of course can be restored or formated on a Mac computer.
I am not too sure, it can be a bad contact between the cable plug with your iPod causing the problem. Otherwise, see doing the following helps
For Mac computer
1. Open the disk utility, hope your iPod appears there (left hand side), highlight it
2. Go to Tab “Partition”, click either “Delete” or “Partition”, if fails, skip this step and go to 3
3. Go to Tab “Erase” , choose Volume Format as “MAC OS Extended (Journaled), and click Erase, again if fails, skip it and go to 4
4. Same as step 3, but open the “Security Options....” and choose “Zero Out Data” before click Erase. It will take 1 to 2 hours to complete.
5. Eject your iPod and do a Reset
6. Open the iTunes 7 and click “Restore”