iPod error code (-3204)

Still using old iPod from 2004, model number A 1059 (or display shows M9282LL also) Not sure if it is considered 'classic' or 'touch' as I don't have the instruction manual (was gifted to me) Recently sync thru iTunes started acting up. Cannot sync music any longer. Have done reset numerous times. iTunes and Mac are up to date. Have restarted Mac numerous times. Have tried all support base suggestions- no luck. Sync will start and then error code appears: 'Attempting to copy to the disk "iPod" failed. An unknown error occurred (-3204)'. I deliberately attempt to re-sync iTunes purchased songs in my library and then iPod will attempt to sync a song that I DID NOT select to sync to iPod and then error message appears. Then I cannot remove the incorrectly synced song unless I do complete reset. Cannot find reference to this error code in support knowledge base. Could this iPod be at the end of its life? Would like to keep using it if possible. Does anyone have any suggestions? Thank you!